Abstract:
A Dyligomer is disclosed. The Dyligomer has the structure                            
     where B is a chemical moiety formed by reactions involving the NCO groups of a diisocyanate having the formulas OCN—B—NCO and the active hydrogens of OH groups of compounds having the formulas A—OH and D—OH, and A and D are chemical moieties formed by the reactions which formed B, and wherein A and D include, in their structures, at least two active hydrogens which are parts of OH groups and at least one ethylenic double bond. 
     Also disclosed are polymerizable compositions comprising Dyligomers and their use to produce structural panels that are admirably suited for use as floors in refrigerated trucks and trailers, and in roofs, sidewalls and load bearing walls for homes and commercial buildings. 
     Blocks which can be used to produce buildings are also disclosed, as is the use of Dyligomers to produce the blocks, and the use of the blocks to produce building structures.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This is a continuation in part of application Ser. No. 09/723,312, filed Nov. 27, 2000 as a continuation in part of application Ser. No. 09/410,793, filed Oct. 1, 1999, itself a continuation in part of application Ser. No. 08/795,123, filed Feb. 7, 1997. Application Ser. No. 09/723,312 is pending; application Ser. No. 09/410,793 is now U.S. Pat. No. 6,284,841, issued Sep. 4, 2001; while application Ser. No. 08/795,123 is abandoned. Priority is also claimed based upon Provisional application No. 60/011,352, filed Feb. 8, 1996. 
    
    
     FIELD OF THE INVENTION 
     This invention is a structural member and, in particular, is a structural member that was developed for use as a floor for a refrigerated or other truck or trailer, but can also be used as a roof for homes and commercial buildings, as floating and other docks and dock covers, as cross arms for utility poles, as steps, as walks and walkways, as seawalls, as fence posts, as patio decks, as building foundations, as beams, as structural panels, as windows, as piers, as outdoor furniture, as horse trailers, and as stalls and barnyard structures. 
     In another aspect, the invention is an intermediate composition that is admirably suited for use in producing the structural member described above, a Dyligomer, as defined below, which is used in formulating the foregoing intermediate composition, and a cured material that can be produced by subjecting the intermediate composition sequentially to condensation polymerization with an isocyanate and then to addition polymerization. 
     In still another aspect the invention is a wall panel and a block both of which can be used in constructing buildings. 
     BACKGROUND OF THE INVENTION 
     Refrigerated trucks and trailers usually have aluminum floors made up of a number of extruded sections, each of which has a plurality of parallel, longitudinally-extending channels. Adjacent ones of the channels have common sidewalls, and webs which are parallel to one another and are structurally integral with opposite edges of the sidewalls. The sections are welded together to make an entire floor, which may have inside dimensions as great as 102 inches (2.6 meters) by 52½ feet (16 meters). The aluminum floor must be insulated from the metal of the truck or trailer by which it is supported. This is usually accomplished by attaching spaced transverse wooden members to the supporting metal of the truck or trailer, and attaching the aluminum floor to the wooden members. After the assembly is complete, a froth foam is injected from a wand into the spaces which are below the floor and between the wooden members, where the floor is unsupported. Such floors leak, and must be replaced frequently, to a large extent because movement of a trailer or truck while in operation on a highway often exerts enormous forces tending to strip screws that are supposed to hold the floor to the trailer or truck and, as a consequence, stripping frequently occurs after a short time of service. Wet floors are particularly subject to this stripping. 
     Isocyanates and compositions that are polymerizable by condensation of the NCO groups of isocyanates with compounds having active hydrogens have been used widely since World War II to produce a broad spectrum of products ranging from coating compositions to medical appliances. 
     BRIEF DESCRIPTION OF THE INSTANT INVENTION 
     The instant invention is based upon the discovery of a structural member made up of the aluminum floor described above, or another floor that is similar in design, but made of thinner aluminum or of another metal, and a cellular material having urethane groups in its molecular structure and an apparent density of at least 8 pounds per cubic foot (0.13 gm per cm3) bonded to the aluminum because of chemical affinity between the aluminum and the foam. As is subsequently explained in more detail, it is also desirable to compound the urethane to promote adhesion. As a consequence of its being in intimate contact with and bonded to the aluminum floor, the urethane foam supports the floor throughout its entire surface. Preferably, the structure also includes, as a substrate, a sheet of a second material, such as expanded polystyrene, plywood or the like, to which the urethane foam is also bonded because of the chemical affinity between the foam and the substrate. Most desirably, the second sheet is also the aluminum floor described above, with its parallel channels extending in a different direction than do the channels in the first floor, e.g., at right angles to the channels of the first floor. The structural member according to the invention has been found to be water tight and to have strength properties which indicate that it should have substantially extended service life by comparison with the previously described floor. The structural member can also be produced from sheet materials having the same shape as the aluminum floor, but made of metals other than aluminum, and can have various shapes other than that of the floor. 
     In another aspect, the instant invention is based upon the discovery of certain compounds, subsequently herein “Dyligomers”, which can serve as monomers in a polycondensation reaction with a polyisocyanate and can also serve as monomers in an addition propagation reaction with an unsaturated cross lining monomer. These Dyligomers can be produced from diisocyanates, the triglyceride of ricinoleic acid, and such compounds as 1,3-propanediol, 1,4-butanediol and 1,4-but-2-enediol; they can be mixed with other compounds which have active hydrogens, are ethylenically unsaturated, or both, and fillers, catalysts, water and the like, and the mixtures can be condensed to a thermoset condition with the same diisocyanate used to produce the Dyligomer, with another diisocyanate, or with a polyisocyanate. The thermoset condensate then cures further by addition polymerization involving the ethylenic unsaturation of the ricinoleic acid triglyceride or other ethylenically unsaturated compound moiety of the Dyligomer, or both. The triglyceride of ricinoleic acid, which is the principal constituent of castor oil, is an example of a compound which is capable of serving as a monomer in a polycondensation reaction with a diisocyanate and is also capable of serving as a monomer in an addition propagation reaction with an unsaturated cross linking monomer, having three hydroxyl groups which are at least potentially capable of a polycondensation reaction with a polyisocyanate and three ethylenic                           
     double bonds which are at least potentially capable of an addition propagation reaction with an unsaturated crosslinking monomer. 
     Other examples of compounds which are capable of undergoing both types of reaction include 1,2,3-trihydroxy propene, with three hydroxyl groups and one ethylenic double                           
     bond, 1,3-propene diol with two hydroxyl groups and one ethylenic double bond, and 1,4-but-2-ene diol, with two hydroxyl groups and one ethylenic double bond. 
     While these and other compounds can serve as monomers in a poly-condensation reaction with a polyisocyanate and can also serve as monomers in an addition propagation reaction with an unsaturated cross linking monomer, their use in practicing the instant invention is only as starting materials in producing Dyligomers, which can also serve as monomers in both polycondensation reactions and in addition propagation reactions. An example of such a Dyligomer, which can be produced by reaction of one molecule of the triglyceride of ricinoleic acid and one molecule of 1,4-but-2-ene diol with one molecule of 2,4-toluene diisocyanate (“TDI”), has the following structure, and is hereinafter called “Dyligomer I”:                           
     Dyligomer I has four ethylenic double bonds and three hydroxyl groups; it can be stored for extended periods of time. 
     THE PRIOR ART 
     U.S. Pat. No. 2,787,601, granted Apr. 2, 1957 to Detrick et al., discloses the production of a cellular plastic material by reaction of an arylene diisocyanate with a fatty acid triglyceride, citing “German Plastics Practice,” De Bell, Goggin and Gloor, 1946, pp. 316 and 463-465 as authority for the statement (column 1, second paragraph of the patent): 
     “Cellular plastic products or plastic foams have been prepared in which isocyanates are used as one of the reactants * * *. In these products the cellular materials are prepared from alkyd resins which contain free carboxy groups.” 
     The patent says that its cellular plastic product is prepared in two steps, a first in which a prepolymer is made by reacting a fatty acid triglyceride containing hydroxy groups with enough of a diisocyanate that, when not more than 47.5% of the total isocyanate groups in the diisocyanate have reacted with the hydroxy groups on the fatty acid radicals, there are no longer any remaining hydroxyl groups, and a second step in which the prepolymer is reacted with water and a tertiary amine catalyst. Upon addition of the water and the tertiary amine catalyst, the patent says, the reaction mass immediately begins to foam due to the reaction of the unreacted isocyanate groups with water to form CO 2  and substituted ureas. The following structure can be postulated, it is said, for the prepolymer produced by reaction of the triglyceride of ricinoleic acid with 2,4-TDI:                           
     U.S. Pat. No. 5,306,798 discloses a “polyurethane embedding composition” suitable for use in a dialyzer, and produced from an A Component containing a large proportion of castor oil and a modified diphenylmethane diisocyanate (“MDI”) B Component. One example of a Component A is composed of 5 parts by weight of a polyether-polyol, 94.95 parts by weight of castor oil and 0.05 part by weight of a catalyst composed of di-n-octyltin bis(2-ethylhexyl thioglycolate) and mono-n-octyltin tris(2-ethylhexyl thioglycolate). The patent discloses the preparation of the modified MDI B component (NCO content of 23 percent by weight) by reacting 4,4′-MDI with a mixture of dipropylene glycol and a polyoxypropylene glycol having a hydroxyl number of 250. 
     U.S. Pat. No. 5,290,632 discloses a Component A of a two component formulation as comprising castor oil and a low molecular weight polyol while component B is a polymeric MDI. An elastomer is an alternative constituent of component A. Examples of polymeric MDI&#39;s are said to be available from Dow Chemical under the registered trademark PAPPI 2027 (average molecular weight 340-380, average functionality 2.6-2.7) and under the designation “Mondur XP-744”. 
     U.S. Pat. No. 5,278,223 is concerned with the polyol component of a urethane formulation, which is required to include (1) branched chain polyols with ester and ether groups, (2) glycerol esters, e.g., castor oil and (3) low viscosity monofunctional alcohols of oleophilic character. The reaction of such a polyol constituent with technical methylene diphenyldiisocyanate “MDI”, TDI or the like is disclosed. 
     U.S. Pat. No. 5,166,301 discloses a prepolymer made from methane dicyclohexyl diisocyanate, a polyoxypropylene ether polyol, methane-dicyclohexyl diisocyanate and a silane, and reaction of the prepolymer with a component composed mainly of polyoxypropylene ether polyol and diethyltoluene diamine plus minor amounts of m-xylene diamine, organo-bismuth and water. Castor oil is named as a “hydroxy functional moiety”. 
     U.S. Pat. No. 5,157,101 discloses the reaction of liquid polyisocyanate from Mobay (“Mondur PF”, 26.6 weight percent NCO) with polybutadiene polyols and amines. 
     U.S. Pat. No. 5,155,165 discloses the reaction of isocyanates or an isocyanate terminated prepolymer with polyhydroxy compounds, which are broadly defined, by a process which produces “polyurethane polyurea particles” which can be, but are not necessarily, pigmented. 
     U.S. Pat. No. 5,061,776 discloses a thermal transfer adhesive composed of 30 to 70 weight percent of an aliphatic diisocyanate or triisocyanate prepolymer, 5 to 15 weight percent of a polyether diol or triol, 20 to 40 weight percent of castor oil, 5 to 20 weight percent of an epoxy resin containing 2 or more hydroxyl groups and 0.006 to 0.008 weight percent of a catalyst for the reaction of isocyanate groups with hydroxyl groups. Dibutyl tin dilaurate is said to be the preferred catalyst. 
     U.S. Pat. No. 4,990,586 discloses the production of a polyurethane by reaction between a polyisocyanate and a polyol in the presence of a diphenyl methane diamine with one amine group and either one or two alkyl group substituents on each phenyl. The preferred polyol is said to be castor oil. 
     U.S. Pat. No. 5,021,535 discloses an abrasion resistant urethane composition for automobile undercoating made from unmodified castor oil and MDI-alkylene oxide prepolymers. The castor oil can be modified by an addition of a cyclohexanone-formaldehyde condensate and can be further modified by an addition of a neopentyl glycol adipic acid reaction product. 
     U.S. Pat. No. 4,990,586 discloses the production of a polyurethane by reaction between a polyisocyanate and a polyol in the presence of a diphenyl methane diamine with one amine group and either one or two alkyl group substituents on each phenyl. The preferred polyol is said to be castor oil. 
     U.S. Pat. No. 4,987,204 discloses a coating composition “comprising 2-100 parts by weight of fluororesin, 5-100 parts by weight of a silicone oil, and a solvent to 100 parts of a urethane prepolymer * * * comprising a polyol, castor oil polyol, and a polyisocyanate * * *.” 
     U.S. Pat. No. 4,968,725 discloses a dental adhesive which includes a urethane prepolymer produced by reacting an isocyanate with a polyol (castor oil is named as an example), a “radical-polymerizable unsaturated monomer and a photopolymerization initiator, and can also include a polymerizable phosphoric ester. 
     U.S. Pat. No. 4,877,829 discloses a “novel polyurethane resin” for application to exterior surfaces, including concrete roadways, produced from two components, Component A being composed of ricinoleic triglyceride (conveniently as castor oil) and a low molecular weight polyol (e.g., glycerol) and Component B being composed of either a mixture of MDI isomers or a mixture of MDI with a prepolymer made by reacting MDI with an alkylene oxide. An elastomer is an optional ingredient of the first component. A Table indicates the following ranges of ingredients in parts by weight to be workable: Castor oil 90 to 140, low molecular weight polyol 2 to 10 and Modified MDI 50 to 110. Up to 120 parts of an elastomer and up to 50 parts of molecular sieves can be used in the non-MDI Component A. 
     U.S. Pat. No. 4,877,455 discloses the autoclaving of castor oil with dicyclopentadiene and hydroxyethyl methacrylate. A maximum temperature of 265° C. and a maximum pressure of 80 psi are reported. The product, which is called a graft polyol, when reacted with polymeric MDI (NCO/OH 1.05), produced a urethane said to be considerably more resistant to certain solvents by comparison with urethanes produced from the unmodified castor oil. 
     U.S. Pat. No. 4,859,735 discloses “Novel polyurethane formulations especially useful as membranes of the protection of bridge deckings. The polyurethane is prepared by mixing two components, A and B. Component A comprises castor oil modified with a ketone-formaldehyde condensate and also preferably contains an elastomer. Component B is a modified MDI, being a mixture of diphenylmethane diisocyanate and its reaction product with a low molecular weight poly(oxyalkylene). 
     U.S. Pat. No. 4,789,705 discloses a resin composition comprising a polyisocyanate having an isocyanurate ring obtained by reacting at least one diisocyanate (alkylene, cycloalkylene or aralkylene) with a diol having 10 to 40 carbon atoms or with a polyester polyol (hydrogenated castor oil is said to be “within the scope of the polyester polyol) containing 12-hydroxystearic acid as an essential component in the presence of an isocyanuration catalyst and a nonpolar organic solvent. 
     U.S. Pat. No. 4,742,087 discloses a prepolymer which contains an excess of an isocyanate component having an average of 2 to 4 NCO groups and a polyol component comprised of an oleochemical polyol prepared by epoxidation of an olefinically unsaturated triglyceride such as castor oil and ring opening with an alcohol. 
     U.S. Pat. No. 4,677,157 discloses a part A composed, in weight percent, of 62.0 4,4′diphenylnethane diisocyanate, 15.0 polyether polyol, 18.0 castor oil, 1.0 carbon black, 3.0 fumed silica and 1.0 organic thixatrope and mixing part A with an equal volume of Part B composed of 30.0 polyether polyol, 25.0 N,N,N,N-tetrakis(2-hydroxypropyl) ethylene diamine and 45.0 fillers. 
     U.S. Pat. No. 4,659,748 discloses urethane formulations for repairing cementitious roadways. Excess NCO groups react with moisture that is naturally present. Castor oil and glyceryl trihydroxy oleate are named as examples of organic compounds which react with polyisocyanates. Dibutyl tin dilaurate is named as a catalyst. 
     U.S. Pat. No. 4,640,801 discloses the autoclaving of castor oil with dicyclopentadiene and hydroxyethyl methacrylate. A maximum temperature of 265° C. and a maximum pressure of 80 psi are reported. The product, which is called a graft polyol, when reacted with polymeric MDI (NCO/OH 1.05), produced a urethane said to be considerably more resistant to certain solvents by comparison with urethanes produced from the unmodified castor oil. 
     U.S. Pat. No. 4,603,188 discloses a urethane composition which has a polyhydroxyl component and a polyisocyanate component. The polyhydroxyl component is made up of 80 to 10 percent by weight of an interesterification product of castor oil and a substantially non-hydroxyl-containing naturally occurring triglyceride oil and 20 to 90 percent by weight of a polybutadiene based polyol. The interesterification product can also contain a low molecular weight polyol. 
     U.S. Pat. No. 4,598,136 discloses aliphatic embedding masses prepared by preparing a prepolymer having NCO groups by reacting at least one aliphatic diisocyanate with castor oil or a mixture of castor oil with other hydroxyl compounds, e.g., trimethylol propane, and reacting the prepolymer with a mixture containing castor oil, trimethylol propane and N-methyldiethanol amine. 
     U.S. Pat. No. 4,582,891 discloses a urethane coating composition. The urethane is produced from a polyol component composed of “a castor oil polyol alone or a mixture of a castor oil polyol and a low molecular weight polyol” and a polyisocyanate component. The “castor oil polyol” can be castor oil, an interesterification product of castor oil and ethylene oxide or the like, an esterification product of ricinoleic acid and an ethylene oxide or the like adduct of dipropylene oxide or the like. TDI and MDI are named as isocyanates. Dibutyl tin dilaurate is disclosed as a component of a polyol composition, along with castor oil. 
     U.S. Pat. No. 4,555,536 discloses a polyurethane coating composition produced from (1) a polyol mixture of castor oil or a polyol derived from castor oil and an amine polyol produced by addition reaction of an alkylene oxide with ammonia, an aliphatic amine or the like, and (2) a polyisocyanate compound. 
     U.S. Pat. No. 4,551,517 relates to a two-component polyurethane adhesive produced by mixing an isocyanate having a functionality of from 2 to 10 with a liquid mixture of anhydrous polyols having more than 10 carbon atoms and 2 or more hydroxyl groups, obtained by reacting (1) epoxidized higher fatty alcohols, (2) epoxidized higher fatty acid esters or (3) epoxidized higher fatty acid amides with aliphatic or aromatic alcohols having a functionality of 1 to 10, with difunctional or trifunctional phenols, or with both, with opening of the epoxide ring. Transesterification of the fatty acid esters, subsequent reaction with C2 to C4 epoxides, or both, is also disclosed. In two examples, the polyols are produced by ring opening epoxidized soy bean oil with methanol. Comparative examples are said to show the superiority of the adhesive of the invention over urethanes made from castor oil. 
     U.S. Pat. No. 4,433,128 is directed to an embedding mass composed of a polyurethane obtained through reaction of an aromatic polyisocyanate with a mixture of castor oil and trimethylolpropane “pre-adduct” and a polypropyleneglycol or a mixture of a polypropyleneglycol and trimethylpropane in the presence of a catalyst which is a mixture of a dialkyl tin dicarboxylate and an aliphatic mono- or di-amine. The patent discloses the production of a Component A having an isocyanate content of 18.85 percent from a liquid polyisocyanate based upon MDI, castor oil and trimethylolpropane, the production of a Component B from polypropylene glycol, trimethylolpropane, dibutyl tin dilaurate and 1,4-diasabicyclo(2,2,2)-octane, and the mixing of the two components to produce casting resins. Several German patent applications are acknowledged as prior art, including DE-OS 28 13 197, which is said to disclose the production of “polyurethanes” by reacting an aromatic polyisocyanate with a mixture of castor oil and trimethylol propane to produce a pre-adduct, and polymerizing the pre-adduct with castor oil or a mixture of castor oil with trimethylol propane. 
     U.S. Pat. No. 4,391,964 is directed to a potting medium composed of a polyurethane obtained through reaction of a polyisocyanate with a mixture of castor oil and trimethylolpropane “pre-adduct” and reaction of the prepolymer with castor oil or a mixture of castor oil with trimethylolpropane for cross lining. A titanium alkylate, e.g., titanium tetrabutylate, is used as a catalyst. 
     U.S. Pat. No. 4,378,441 discloses resinous products produced by reacting (A) an alkali metal silicate, (B) an organic monohydroxy compound having a substituent which will split off during the reaction, and (C) a polycarboxylic acid and/or a polycarboxylic acid anhydride. Castor oil can be substituted for a small portion of the polycarboxylic acid. 
     U.S. Pat. No. 4,375,521 discloses a vegetable oil extended polyurethane produced by reacting an isocyanate terminated polyisocyanate with a polyol (which can be castor oil) in the presence of a vegetable oil such as soybean, safflower, corn, sunflower, linseed, oiticica, coconut, cottonseed, peritta, palm, olive, rape or peanut. 
     U.S. Pat. No. 4,371,683 discloses that castor oil can be substituted for up to 85 percent of the polyol in an adhesive composed of the reaction product of a novolac, an oxirane and a polyisocyanate. 
     U.S. Pat. No. 4,344,873 is directed to a potting medium composed of a polyurethane obtained through reaction of a polyisocyanate with a mixture of castor oil and trimethylolpropane “pre-adduct” and reaction of the prepolymer with castor oil or a mixture of castor oil with trimethylolpropane for cross ling. A dialkyl tin compound is used as a catalyst. 
     U.S. Pat. No. 4,170,559 discloses the production of a prepolymer (NCO content about 16.2 percent) from 204 g polyoxypropylene glycol (M.W. 400), 205 g castor oil and 795 g MDI, and cure of such a prepolymer with an ester of a polyhydric alcohol having 2 or three OH groups and an aliphatic acid having at least 12 carbons atoms and at least one OH group or epoxy group. The following U.S. patents are cited as disclosing the preparation of prepolymers: U.S. Pat. Nos. 2,625,531; 2,625,532; 2,625,535; 2,692,873; and 2,702,797. 
     Dyligomer I, above, and other related dyligomers are disclosed in his U.S. Pat. No. 6,284,841, supra, but the present inventor is not aware of any prior art disclosing Dyligomer I or an equivalent thereof, i.e., a compound that has no NCO groups, and is composed of a chemical moiety that is derived from a diisocyanate, and is bonded through urethane groups to two additional chemical moieties which have a plurality of active hydrogens and a plurality of ethylenic double bonds so that they are capable of reacting with an isocyanate to form urethane linkages and, as a consequence, a three-dimensional cross linked polymer, and subsequently and independently, with a cross linking monomer in an addition propagation reaction. Accordingly, he is not aware of prior art disclosing an intermediate composition comprising such a Dyligomer and a cross linking monomer that is sufficiently fluid that fillers it may contain are wet effectively. Finally, he is not aware of prior art disclosing a material that will cure to a thermoset condition which is produced by mixing an isocyanate with such an intermediate composition comprising Dyligomer I or an equivalent and a cross liking monomer. 
     OBJECTS OF THE INVENTION 
     Accordingly, it is an object of the invention to provide a dyligomer which can serve sequentially as a monomer in a polycondensation reaction with a polyisocyanate and then as a monomer in an addition propagation reaction with an unsaturated cross liking monomer, because it has both ethylenic groups and active hydrogens in its molecule. The dyligomer, as is subsequently explained in more detail, is composed of three chemical moieties, one of which is a moiety derived from a diisocyanate and is bonded to a first of the other moieties through a urethane group and to the second of the other moieties through a different urethane group. 
     It is another object to provide an intermediate composition composed of a dyligomer, a cross linking monomer reactive by addition polymerization with the double bonds of the dyligomer, a catalyst for the reaction of the dyligomer with an isocyanate to form a urethane, and a free radical catalyst for the addition polymerization of the cross linker. 
     It is a further object to provide a thermoset material produced by condensing the intermediate composition with the diisocyanate used to produce the dyligomer, with another diisocyanate, or with an isocyanate having more than two NCO groups per molecule. 
     It is yet another object of the invention to provide a thermoset condensate that has been cured further, after polycondensation, by an addition polymerization reaction involving the ethylenic unsaturation of the dyligomer. 
     It is still another object to provide a structural member. 
     It is yet another object to provide a structural panel that is admirably suited for use as a floor in refrigerated trucks and trailers, and in roofs, sidewalls and load bearing walls for homes and commercial buildings. 
     It is still another object to provide structural members that are admirably suited for use as floating and other docks and dock covers, as cross arms for utility poles, as steps, as walks and walkways, as seawalls, as fence posts, as patio decks, as building foundations, as beams, as structural panels, as piers, as windows, as outdoor furniture, as horse trailers, and as stalls and barnyard structures. 
     It is yet another object to provide a block which is admirably suited for use in sidewalls and load bearing walls for homes and commercial buildings. 
     BRIEF DESCRIPTION OF THE INSTANT INVENTION 
     In one aspect, the instant invention is based upon the discoveries that a dyligomer that is stable for extended periods of time can be produced by reacting one molecule of a diisocyanate with two molecules, which can be the same or different, of a compound which has active hydrogens in its structure, and at least one of which has an ethylenic double bond, that the Dyligomer can be mixed with various additives, e.g., a copolymerizable monomer, an inorganic or organic filler, and a free radical catalyst, to produce an intermediate composition that is stable for an extended period of time, and can be mixed with an appropriate amount of a diisocyanate or polyisocyanate to produce a material in which the Dyligomer serves sequentially as a monomer in a polycondensation reaction with the diisocyanate or polyisocyanate and then as a monomer in an addition propagation reaction with the copolymerizable monomer. This material, prior to cure, can be introduced into suitable molds to produce various articles of manufacture, e.g., the previously mentioned structural member that was developed for use as a floor for a refrigerated or other truck or trailer, but can also be used as a roof for homes and commercial buildings, as floating and other docks and dock covers, as cross arms for utility poles, as steps, as walks and walkways, as seawalls, as fence posts, as patio decks, as building foundations, as beams, as structural panels, as windows, as piers, as outdoor furniture, as horse trailers, and as stalls and barnyard structures. 
     Dyligomer I, as previously explained, can be produced by reacting one molecule of ricinoleic acid triglyceride with one molecule of 2,4-TDI, and one molecule of 1,4-but-2-ene diol. Dyligomer II, which has the following structure, is produced when one molecule of ricinoleic acid triglyceride reacts with one molecule of 2,4-TDI, and one molecule of glycerol:                           
     Similarly, one molecule of ricinoleic triglyceride can react with one molecule of 2,4-TDI, and one molecule of 1,4-butane diol to produce a dyligomer (hereafter Dyligomer III) having the following structure:                           
     Other dyligomers that can be produced by reacting one molecule of 2,4-TDI with two molecules of at least one other compound having an active hydrogen are identified in the following table: 
     
       
         
               
               
               
               
             
           
               
                   
               
               
                   
                   
                   
                 Second reactant 
               
               
                   
                 Diisocyanate 
                 First reactant having 
                 having an 
               
               
                 Name 
                 reactant 
                 an active hydrogen 
                 active hydrogen 
               
               
                   
               
             
             
               
                 Dyligomer 
                 2,4-TDI 
                 Ricinoleic acid triglyceride 
                 n-butanol 
               
               
                 IV 
               
               
                 Dyligomer 
                 2,4-TDI 
                 Ricinoleic acid triglyceride 
                 1,2,3-trihydroxy 
               
               
                 V 
                   
                   
                 propene 
               
               
                 Dyligomer 
                 2,4-TDI 
                 1,2,3-trihydroxy propene 
                 1,2,3-trihydroxy 
               
               
                 VI 
                   
                   
                 propene 
               
               
                 Dyligomer 
                 2,4-TDI 
                 1,4-but-2-ene diol 
                 1,2,3-trihydroxy 
               
               
                 VII 
                   
                   
                 propene 
               
               
                 Dyligomer 
                 2,4-TDI 
                 1,4-but-2-ene diol 
                 1,4-but-2-ene diol 
               
               
                 VIII 
               
               
                   
               
             
          
         
       
     
     The structures of the dyligomers identified in the foregoing table are presented below:                           
     It will be appreciated that Dyligomers I through V can all be represented by the following formula, where R is alkyl, hydroxy alkyl, dihydroxy alkyl, or hydroxy alkenyl:                           
     It will also be appreciated that, more generally, the foregoing dyligomers can be represented by the formula                           
     where B is a chemical moiety formed by reactions involving the NCO groups of a diisocyanate having the formula, 
     
       
         OCN—B—NCO 
       
     
     and the active hydrogens of OH groups of compounds having the formulas 
     
       
         A—OH and D—OH 
       
     
     and A and D are chemical moieties formed by the reactions which formed B, and wherein A and D include, in their structures at least two active hydrogens which are parts of OH groups and at least one ethylenic double bond. In addition, it will be appreciated that the properties of the diligomer represented by Formula I depend upon the identity of R. For example, Dyligomer IV has two OH groups and three ethylenic double bonds available for condensation polymerization with an isocyanate and for addition polymerization respectively. However, the geometry of the molecule does not favor either type of reaction. Dyligomer I, on the other hand, has an additional ethylenic double bond and an additional OH group, and the geometry of the molecule favors reaction of both of the additional groups. As might be expected, available evidence indicates that Dyligomer I, by comparison with Dyligomer IV, is capable of a higher degree of condensation polymerization with an isocyanate and of a higher degree of addition polymerization with a cross-linking molecule. Similarly, Dyligomer II and Dyligomer III appear to be capable of a higher degree of condensation polymerization with an isocyanate. 
     Dyligomers can also be produced from: 
     (A) other diisocyanates, the triglyceride of ricinoleic acid, and n-butanol, 1,4-butane diol, glycerol, 1,2,3-trihydroxy propene, and 1,4-but-2-ene diol, 
     (B) diisocyanates, the triglyceride of ricinoleic acid and various polyesters and polyethers having free alcoholic OH groups (such polyesters and polyethers are commercially available, and are sold for use in producing urethanes), and 
     (C) diisocyanates, n-butanol, 1,4-butane diol, glycerol, 1,4-but-2-ene diol, 1,2,3-trihydroxy propene, various polyesters and polyethers having free alcoholic OH groups (such polyesters and polyethers are commercially available, and are sold for use in producing urethanes) and equivalents for the triglyceride of ricinoleic acid. 
     Examples of compounds which can be used as equivalents for the ricinoleic acid triglyceride in producing dyligomers include ricinoleic and other fatty acid monoglycerides, ricinoleic and other fatty acid diglycerides and fatty acid esters of various polyesters and polyethers having free alcoholic OH groups, for example, ones which are commercially available for reaction with isocyanates to produce urethanes; and fatty acid monoesters of glycols, and of fatty acid esters which have at least one free alcoholic OH group, and are formed by esterification of alcoholic OH groups of various polyesters and polyethers with fatty acids. 
     In theory, it is possible to produce dyligomers from diisocyanates, n-butanol, 1,4-butane diol, glycerol, 1,4-but-2-ene diol, various polyesters and polyethers having free alcoholic OH groups (such polyesters and polyethers are commercially available, and are sold for use in producing urethanes) and fatty acids. As a practical matter, however, it is necessary to control the rates of reaction between the diisocyanate and the fatty acid, and between the diisocyanate and the n-butanol or the like so that dyligomers composed of moieties from all three reactants are formed. 
     The foregoing and other dyligomers can be mixed with a cross linker such as styrene, diallyl phthalate, triallyl cyanurate, a free radical catalyst and a catalyst such as cobalt naphthenate for the condensation of an isocyanate with a reactive hydrogen of an OH group to produce an intermediate that is stable for extended periods of time, and can be mixed with a diisocyanate or a polyisocyanate to produce a polymerizable composition in which the dyligomers and the diisocyanate or polyisocyanate undergo condensation polymerization to form urethane linkages and a three dimensional cross linked polymer and, subsequently and independently, the dyligomer reacts with the cross linker in an addition propagation reaction. The intermediate composition can also contain various fillers, a colorant, and water, if a cellular product is desired. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram showing apparatus which can be used to produce a structural member according to the invention. 
     FIG. 2 is a vertical sectional view showing a mold which is a part of the apparatus of FIG. 1 with an aluminum floor of the kind described above positioned in the mold. 
     FIG. 3 is a view in vertical section similar to FIG. 2, but showing the mold and aluminum floor after a foamable polyol/isocyanate or the like composition has been introduced into the mold. 
     FIG. 4 is a vertical sectional view similar to FIG. 3, but showing the mold in a closed position and a sheet of expanded polystyrene or the like on top of the foamable polyollisocyanate or the like composition. 
     FIG. 5 is a view in vertical section similar to FIG. 4, but showing the assembly after the polyol/isocyanate composition has foamed so that it is confined within the closed mold between the expanded polystyrene or the like sheet and the aluminum floor. 
     FIG. 6 is a perspective view showing the structural member which is produced after cure of the polyol/isocyanate composition of FIGS. 3-5 to a foamed, thermoset condition. 
     FIG. 7 is a vertical sectional view of the aluminum floor of FIGS. 2-6, showing a typical longitudinally extending joint between two adjacent lengths of the material. 
     FIG. 8 is a view in vertical section taken along the line  8 — 8  of FIG. 6, and showing further details of the structural member. 
     FIG. 9 is vertical sectional view showing another embodiment of a structural member according to the invention. 
     FIG. 10 is a view in vertical section showing still another embodiment of a structural member according to the invention. 
     FIG. 11 is a vertical sectional view similar to FIG. 3, illustrating an intermediate stage in the production of yet another embodiment of a structural member according to the invention; FIG. 11 shows a mold, two aluminum floors and a foamable polyol/diisocyanate composition in the mold. 
     FIG. 12 is a view in vertical section showing the mold and the aluminum floors of FIG. 11 after the foamable composition shown in that view has expanded and cured to a urethane. 
     FIG. 13 is a view in vertical section taken along the line  13 — 13  of FIG. 12, and showing the relationships among the two aluminum floors and the foamed urethane. 
     FIG. 14 is a fragmentary, vertical sectional view showing the final product, which is one of the presently preferred structural members according to the invention, which is produced from the intermediates of FIGS. 12 and 13; the member is shown situated in a mold which is also shown in FIGS. 11 through 13. 
     FIG. 15 is a fragmentary view in vertical section showing another of the presently preferred structural members according to the invention; the member is shown in a mold in which it can be produced. 
     FIG. 16 is a fragmentary, horizontal sectional view showing still another of the presently preferred structural members according to the invention; the member, which can be used as a fence post is shown in a mold in which it can be produced. 
     FIG. 17 is a view in vertical section taken along the line  17 — 17  of FIG.  16 . 
     FIG. 18 is a fragmentary, vertical sectional view showing yet another of the preferred structural members according to the invention. 
     FIG. 19 is a view in vertical section taken along the line  19 — 19  of FIG.  18 . 
     FIG. 20 is a plan view of a part of a mold that has been used to produce a strip of cured material about 8 feet long, 4 inches wide and ½ inch thick. 
     FIG. 21 is a view in elevation showing the mold part of FIG. 20 with a first cover on the mold part. 
     FIG. 22 is an elevational view showing the mold part of FIG. 20 with a second cover on the mold part. 
     FIG. 23 is a front view in elevation showing a window fame according to the invention; the frame has opposed side guides, an upper stop and a sill. 
     FIG. 24 is sectional view taken along the line  24 — 24  of FIG. 23, and showing the structures of the opposed side guides of the FIG. 23 window. 
     FIG. 25 is a view in section taken along the line  25 — 25  of FIG. 23, and showing the structure of the sill of the FIG. 23 window. 
     FIG. 26 is a view in front elevation showing a mold in which the window of FIG. 23 can be produced. 
     FIG. 27 is a view showing the mold of FIG. 26 in a position in which a polymerizable composition according to the invention can be poured into the mold to produce the window of FIG.  23 . 
     FIG. 28 is an elevational view showing the window frame of FIG. 23 mounted in a fragment of a stud wall of a building. 
     FIG. 29 is a perspective view showing a wall panel which is another embodiment of the instant invention. 
     FIG. 30 is a view in perspective showing a mold in which a cement wall of the panel shown in FIG. 29 can be produced. 
     FIG. 31 is a perspective view showing two walls which can be produced in the mold of FIG.  30 . 
     FIG. 32 is a view in perspective showing a wall which can be produced in the mold of FIG. 30 in a mold in which other walls of the panel shown in FIG. 29 have been produced. 
     FIG. 33 is a schematic diagram showing the steps in the production of a cellular core of the wall panel of FIG.  29 . 
     FIG. 34 is a view in perspective showing an end, the top and an outer side of a composite block which is a key component of a particularly advantageous wall structure according to one embodiment of the instant invention. 
     FIG. 35 is a perspective view of a fragment of the block of FIG. 34, showing parts of the top and of the outer side, and the end opposite that shown in FIG.  34 . 
     FIG. 36 is a view in perspective showing a portion of the particularly advantageous wall structure according to one embodiment of the instant invention of which the block of FIGS. 34 and 35 is a key component. 
     FIG. 37 is a vertical sectional view taken along the line  37 — 37  of FIG.  36 . 
     FIG. 38 is a view in perspective similar to FIG. 36, but showing a different portion of the wall structure of which the block of FIGS. 34 and 35 is a key component. 
     FIG. 39 is a perspective view similar to FIG. 34, but showing a composite block having different dimensions. 
     FIG. 40 is a view in perspective similar to FIG. 35, but showing the block of FIG.  39 . 
     FIG. 41 is a plan view showing a block that can be used to connect two walls which intersect at right angles. 
     FIG. 42 is a view similar to FIG. 41 of another block that can be used to connect two walls which intersect at right angles. 
     FIG. 43 is a perspective view of a foundation showing a spline arrangement that can be used to construct intersecting walls. 
     FIG. 44 is a view in perspective showing a block which is advantageously used where two walls intersect. 
     FIG. 45 is a perspective view showing another block which is advantageously used where two walls intersect. 
     FIG. 46 is a view in perspective showing a block which can be used when it is desired to lock together two walls which intersect. 
     FIG. 47 is a plan view of a lock which can be used to lock together two walls which intersect. 
     FIG. 48 is a view in perspective showing another block which can be used when it is desired to lock together two intersecting walls. 
     FIGS. 49 and 50 are perspective views of still another block which is particularly advantageous for use in the top course of a wall structure according to one embodiment of the instant invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Example 1, below, describes the production of Dyligomer I. In Example 1, and elsewhere herein, the terms “parts” and “percent” refer to parts and percent by weight, unless otherwise indicated. The following abbreviations are used: cm means centimeter or centimeters; g means gram or grams; kg means kilogram or kilograms. 
     EXAMPLE 1 
     Dyligomer I was produced from castor oil which had an assay of 89 percent ricinoleic triglyceride, a hydroxy No. of 161 to 169 and an iodine No. of 81 to 89, an isomer blend of 80 percent 2,4-TDI and 20 percent 2,6-TDI, 1,4-but-2-ene diol and dibutyltin dilaurate. The TDI had an NCO content of 50 percent. The castor oil, the dibutyltin dilaurate, and the 1,4-but-2-ene diol were metered into a first static mixer in such proportions that the weight ratio of the castor oil to the 1,4-but-2-ene diol to the dibutyltin dilaurate flowing in the mixer was 930:88:2.5. The effluent from the first static mixer and the TDI were metered into a second static mixer in such proportions that the weight ratio of the castor oil to the 1,4-but-2-ene diol to the dibutyltin dilaurate to the TDI in the second mixer was 930:88:2.5:168. The effluent from the second static mixer was a homogeneous solution which contained Dyligomer I and had an NCO content less than 10 parts per million; the solution was stable, and has been stored at ambient temperature of about 25° C. for extended periods of time without visible sign of phase separation or of change in viscosity. The solution had an OH content of 4.29 percent. There was no refraction of a beam of light shined through the solution. 
     An intermediate composition was then prepared by thorough mixing of 100 parts of the Dyligomer I solution, 28.1 parts of triallyl cyanurate, 1 part of benzoyl peroxide, 1.5 parts of cobalt naphthenate, 1 part of dimethyl aniline, 1.2 parts of a silicone surfactant that is commercially available from Dow Corning under the designation DC 193, 90 parts of 5 micron calcium carbonate (325 mesh), 0.5 part of water and 1 part of a polymeric colorant. 
     A mixture of the intermediate composition and a liquified MDI were then used to produce a structural member according to the instant invention which is indicated generally at  10  in FIG.  6 . The member  10  is composed of an aluminum floor  11 , a cured cellular body  12  of a thermoset material according to the invention, and an expanded polystyrene sheet  13 . The member  10  can be produced in a mold  14  (FIG. 2) which has sidewalls  15 , a bottom  16  and a top  17  which is attached to one of the sidewalls  15  by a hinge  18 . Producing the member  10  involved placing the aluminum floor as indicated generally at  19  on the bottom  16  of the mold  14 , introducing a predetermined quantity of a mixture of liquefied MDI and the intermediate composition produced as described above into the floor  11  inside the mold  14 , placing the expanded polystyrene sheet  18  on top of the mixture, and closing the top  17  of the mold  14 . The mold  14  is shown in FIG. 3 with a quantity of the MDI/intermediate composition, designated generally at  20 , inside the aluminum floor  19 , in FIG. 4 with the expanded polystyrene sheet  13  on top of the MDI/intermediate composition  20  and with the top  17  closed, and in FIG. 5 after the composition  20  has foamed and cured so that it is the thermoset foam  12 . As an incident of the foaming of the composition  20 , the expanded polystyrene sheet  13  has been forced against the top  17  of the mold  14  and the foaming composition has been forced into intimate contact with the aluminum floor  11  and with the expanded polystyrene sheet  13 . 
     There are openings (not illustrated) through the expanded polystyrene sheet; during foaming, expansion of the composition  20 , forces the polystyrene sheet into contact with the mold top, and further expansion forces the foaming composition into and to the tops of the openings, so that the composition can be seen as part of the upper surface of the structural member  10  (FIG. 6, where a pad composed of the thermoset foam which fills one of the openings is designated  21 ). The pads  21  which extend through to the upper surface (in FIG. 6) of the expanded polystyrene sheet  13  are an important part of the structural members  10 . The structural members, when in service as the floor of a refrigerated truck or trailer, are inverted from the position shown in FIG. 6, so that the pads  21  bear on the support members of the truck or trailer, and can be secured in place by screws which extend through the support members, but are thermally insulated by the thermoset foam of the pads  21  from the aluminum of the structural members. 
     The mixture of the liquefied 4,4′-MDI and the intermediate composition of Example 1 was produced in the apparatus of FIG.  1 . The MDI was charged to a vessel  22  (FIG.  1 ), and the intermediate composition was charged to a vessel  23 . The MDI was then pumped from the vessel  22  through a line  24  to a meter  25 , while the composition in the vessel  23  was pumped from the vessel  23  through a line  26  to the meter  25 , which was set to deliver the MDI at a rate of 44.6 parts per minute and the intermediate composition in the vessel  23  at a rate of 100 parts per minute through a line  27  to a mixer  28  where they were rapidly and thoroughly mixed before being discharged through a line  29  into the mold  14  (see, also, FIG.  2 ). The MDI introduced into the line  29  contained substantially 1.05 NCO groups per OH group in the intermediate composition introduced into the line  29 . Parts of the inner surfaces of the sides  15  of the mold  14  (see FIGS. 2-5) were in contact with the MDI/intermediate composition introduced into the mold  14 , and during and after foaming; these surfaces had been sprayed with a 5 percent solution in naphtha of a silicone caulking material that is commercially available from Dow Corning under the designation Silicone II. The aluminum floor in the mold  14  had a wall thickness of 0.08 cm, the horizontal surfaces  30  thereof were 2.14 cm wide, from left to right in FIG.  2 . All of the other horizontal surfaces of the floor  19  were 2.54 cm wide, from left to right in FIG. 2, and all of the vertical surfaces thereof were 2.54 cm high The mold  14  was charged, in about 10 seconds, with 568 g of the composition flowing from the line  28  per 929 cm of aluminum floor surface, disregarding area of the legs which extend vertically in FIG.  2  and the area of the horizontally extending surfaces which face downwardly in FIG.  2 . The sheet  13  of expanded polystyrene, which fills the mold from right to left as shown in FIG. 4 and, in a similar manner, from front to back, was then placed on top of the foamable composition as shown in FIG. 4, and the lid  17  of the mold  14  was closed, and clamped shut. The foamable composition expanded to force the expanded polystyrene sheet into contact with the lid  17  of the mold  14 , and forced itself into intimate contact with the bottom of the expanded polystyrene sheet and with the surfaces of the aluminum floor  19  which were exposed to it. 
     As is noted above, there were openings in the expanded polystyrene sheet  13  when it was placed in the mold  14 . During foaming of the composition, vapor phase components escaped through these openings and from the mold  14 , and the foaming composition forced itself into and through the openings, forming the pads  21  (FIG. 6) into which screws or other threaded members can be turned to attach the structural member  10  to structural parts of a trailer, truck, roof or the like. Since the upper surfaces of the pads  21  were in contact with parts of the lid  17  of the mold  14 , those parts of the lid had also been sprayed with the Silicone II solution described above. The openings into which the foaming composition forces itself to form the pads  21  are provided at least as frequently as necessary to enable the escape of air and vapors from the mold and to provide pads wherever they are needed, e.g., every 12 inches, every 18 inches or every 24 inches, longitudinally of the member  10 . It is customary, in floors for refrigerated trucks and trailers, to provide cross supports every 12 inches; in this case, there should be pads  21  every 12 inches, and there should be at least two, and usually three across the width of the floor. 
     The aluminum floor  19  is commercially available, and, like wood, has sufficient strength that it can be used as a flooring material in trucks and trailers, being capable of supporting fork trucks driven into the trucks or trailers. It is known that the aluminum floor has higher compressive and flexural strengths and a higher modulus of rupture than hardwood, and that the structural member  10  has higher compressive and flexural strengths and a higher modulus of rupture than the aluminum floor  19 . The structural member  10  is also significantly superior to hardwood as a thermal insulating material, and can be made as thick as desired, within relatively wide limits, to provide the desired thermal insulating capability. 
     The liquefied 4,4′-DMI is commercially available from BASF under the trade designation Lupranate M20S. It contains 2.15 NCO groups per methylene group. A similar material is available from Mobay under the designation Mondur MR. Such materials can be produced by reacting 4,4′-MDI having a slightly higher ratio of NCO groups to methylene groups with a small amount of a polyethylene glycol having a molecular weight of about 400. The reaction lowers the NCO to methylene group ratio to 2.15, and produces a homogeneous solution, which is, essentially, a prepolymer. 
     The polymeric colorant used as described in Example 1 was one that includes a chromofor chemically bonded to an OH group, and is commercially available from Miliken Chemicals, Spartanburg, S.C. under the trade designation REACTINT. The hydrogen of the OH group is active, so that it reacts with a free NCO group of the polymerizable composition, with the result the colorant is chemically bonded to the cured material. 
     The static mixer used in the procedure described in Example 1 is commercially available from TAH Industries, Inc., under the trademark STATA-TUBE mixer. It is disclosed in U.S. Pat. No. 4,093,188. The same company markets another mixer under the trademark SPIRAL mixer, which is also suitable. This mixer is disclosed in U.S. Pat. Nos. 4,840,493 and 4,850,705. 
     An aluminum member having the shape of the floor  19 , but made from thin sheet material, was used to produce a structural member similar to a part of the member  10 . The specific member used was so thin that, when it was suspended between two supports which extended transversely of its channels and were separated from one another by twelve inches a load applied in the center of the member caused it to collapse before available instrumentation indicated the magnitude of the load. An identical aluminum member was then placed in the mold  14  Wig. 1); the mold was charged with 568 g per 929 cm of the intermediate/isocyanate composition produced as described above with reference to FIG. 1; a sheet of thin polyethylene was placed over the foamable composition, a sheet of expanded polystyrene was placed in the mold, above the polyethylene sheet; and the lid  17  was closed, and clamped shut. The composition expanded to fill the available space inside the mold  14 , and cured to such an extent that it could be removed from the mold after about 10 minutes; it had an apparent density of about 20 gm per cc. After the foamed composition had cured for about 48 hours, the member, when it was suspended between two supports which were circular in cross section and extended transversely of its channels, and were separated from one another by twelve inches on centers, withstood a load of 4560 pounds before failure. The load was applied by a member that was circular in cross-section that extended laterally across the structural member, and that was spaced six inches on centers from each of the supports. A sharp noise from the member was deemed to indicate failure; it was determined that the foam had pulled away from the metal, and that the metal had collapsed. 
     The procedure described in the previous paragraph was repeated, except that the aluminum member was lined with a thin polyethylene sheet before the foamable composition was poured therein. The polyethylene sheet prevented the foam from adhering to the aluminum so that a body of the foam could be removed from the mold after foaming and initial cure. After the foam had cured for about 48 hours, it was suspended as described above and subjected to a load applied as described. Failure occurred at an applied load of 700 pounds. 
     The aluminum floor  19  comes in 25.4 cm widths, and with outer channels which can be forced together as shown in FIG. 7 to connect adjacent lengths of the material to one another. The floor  19 , as described above, has been used in refrigerated and dry cargo trucks and trailers, and wood has been used in dry cargo trucks and trailers. It has been found that the floor  19  is stronger than wood in this service. Malaysian Kapur, a hardwood that has been found to be suitable for this use, has been found to have a flex strength of 2433 pounds and the following properties: 
     
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Physical property 
                 Test Method 
                 Value 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compressive Strength 
                   
                 D1621 
                 3880 psi. 
               
               
                 Screw holding resistance: 
                 initial 
                 SE14 
                 1865 pounds 
               
               
                   
                 fatigued 
                 E14 
                  318 pounds 
               
               
                   
               
             
          
         
       
     
     A typical urethane foam having a density of 36 pounds per cubic foot (0.58 g per cm 3 ) had a flex strength of 1806 pounds per square inch and a Screw holding resistance of 1510 pounds initial, and 1504 pounds, fatigued (Test Methods SE14 and E14). The tests described above indicate that the structural member  10  has a greater compressive strength and a greater flex strength than does the floor  19 . Therefore, the member  10  has excess strength for use as a floor for a refrigerated or dry cargo truck or trailer, which means that a member  10  made with a floor having thinner walls would have the requisite strength. In general for use as a floor for a refrigerated truck or trailer, the structural member should have a compressive strength of at least about 3500 psi. and flex strength of at least about 2000 pounds. For use as a roof, the member  10  needs only the strength requisite to support a snow load, which is only a few pounds per square inch even for several feet of snow. The structural member  10  can also be used as a sea wall, as a floating dock or as one which rests upon and may be attached to suitable supports, as a foundation for a house or other building, or as a wall or ceiling panel. The thickness of the walls of the aluminum floor  19  and the apparent density of the foam can be varied as necessary to provide the required strength and other properties needed for any of the above uses. In general, increasing the thickness of the walls of the aluminum floor or the amount of foamable composition charged, other factors being equal, increases the strength of the structural panel, and vice versa Similarly, decreasing the amount of urethane composition charged decreases the weight of the structural member, and substituting another foamable composition for the urethane material changes the strength properties and, usually, the apparent density of the thermoset foam that is produced. A decorative finish can be provided on one or both of the major surfaces of the structural member so that it can be used as an insulating wall panel that is pre-decorated on one or both sides. 
     The method described above in Example 1 has been used to produce other dyligomer solutions from the TDI isomer blend described above. Representative ones of the starting materials that were uses and the quantities in parts, are set forth in the following table: 
     
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 2-butene- 
                 1,4-but-2- 
                   
               
               
                   
                 TDI 
                 Castor Oil 
                 1-ol 
                 ene diol 
                 Glycerol 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Example 2 1   
                 168 
                 930 
                  72 
                 — 
                 — 
               
               
                 Example 3 2   
                 168 
                 930 
                 — 
                 — 
                  92 
               
               
                 Example 4 2   
                 168 
                 — 
                 — 
                 176 
                 184 
               
               
                 Example 5 2   
                 168 
                 — 
                 144 
                 — 
                 184 
               
               
                   
               
               
                   1 also contained 2.5 parts of dibutyl tin dilaurate and 1.5 parts of stannous octoate  
               
               
                   2 also contained 2 parts of stannous octoate  
               
             
          
         
       
     
     Dyligomers can also be produced by the procedure of Example 1 from other isocyanates, preferably diisocyanates, for example, from other isomer blends of TDI, from pure 2,4-TDI or from pure 2,6-TDI, from 1,6-hexamethylene diisocyanate, from m-xylene diisocyanate, from dianisidine dilsocyanate, from isophorone diisocyanate and from tolidine diisocyanate. An equivalent amount of the other diisocyanate is merely substituted for the TDI isomer blend in the Example 1 procedure. 
     Pure MDI is difficult to use as a starting material in producing urethanes and Dyligomers according to the instant invention because it is a solid at room temperature. A prepolymer that is a liquid at room temperature and is produced by reacting MDI with a low molecular weight polyethylene glycol or similar material is usually employed as a starting material in producing urethanes containing MDI moieties. Such prepolymers frequently contain more than two NCO groups per molecule and, for that reason, are relatively undesirable starting materials for producing a Dyligomer according to the invention, because the Dyligomers are preferably liquids of low viscosity which are free of NCO groups. If all the NCO groups of the prepolymers are reacted, cross lining occurs, and the viscosity of the product is increased as a consequence. 
     Examples, in parts, of another intermediate composition that can be produced from Dyligomer I and of intermediate compositions that can be produced from the Dyligomers of Examples 2 through 4 are set forth in the following table. Each intermediate composition was produced from 100 parts of the indicated Dyligomer, 1 part of the previously identified colorant, 1 part of dimethyl aniline, and the amount in parts of the other ingredients listed in the table, where “TAC” means trialyl cyanurate, “DAP” means Diallyl phthalate, “BP” means benzoyl peroxide, “t-BPB” means t-butyl peroxybenzoate, and “CoNaph” means cobalt naphthaate. 
     
       
         
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                   
                   
                   
                   
                   
                   
                 Int 
                 Int 
                 Int 
               
               
                   
                 Int II 
                 Int III 
                 Int IV 
                 Int V 
                 Int VI 
                 VII 
                 VIII 
                 IX 
               
               
                 Dyligomer 
                 I 
                 Ex 2 
                 Ex 3 
                 Ex 3 
                 Ex 4 
                 Ex 4 
                 Ex 4 
                 Ex 5 
               
               
                   
               
             
             
               
                 TAC 
                 — 
                 — 
                 21.2 
                 — 
                 — 
                 15.4 
                 — 
                 — 
               
               
                 DAP 
                 40.2 
                 — 
                 — 
                 15.6 
                 — 
                 — 
                  22.6 
                  19.7 
               
               
                 Styrene 
                 — 
                 34.0 
                 — 
                 12.2 
                 18.5 
                 — 
                 — 
                 — 
               
               
                 BP 
                  1.0 
                 — 
                 — 
                 — 
                  1.5 
                 — 
                  2.0 
                  1.5 
               
               
                 t-BPB 
                 — 
                  2.0 
                  2.0 
                  2.0 
                  2.0 
                  2.0 
                 — 
                 — 
               
               
                 CoNaph 
                  1.5 
                  2.0 
                  2.0 
                  2.0 
                  2.0 
                  2.0 
                  1.5 
                  1.5 
               
               
                 CaCO 3   
                 20 
                 20 
                 — 
                 80 
                 — 
                 60 
                 150 
                 100 
               
               
                 Water 
                 — 
                 — 
                  1.0 
                  0.7 
                  0.5 
                 — 
                  0.4 
                  0.6 
               
               
                 DC 193 
                 — 
                 — 
                  2.0 
                  1.5 
                  0.5 
                 — 
                  0.5 
                  0.5 
               
               
                   
               
             
          
         
       
     
     Polymerizable compositions according to the invention can be produced by mixing any of intermediate compositions 2 through 9 with an appropriate amount of the previously identified liquefied MDI or of another polyisocyanate. The amount of the solubilized MDI that is appropriate for mixture with 100 parts of Intermediate II is 60.5, with 100 parts of Intermediate III is 31.0, with 100 parts of Intermediate IV is 53.1, with 100 parts of Intermediate V is 30.2, with 100 parts of Intermediate VI is 104.7, with 100 parts of Intermediate VII is 72.4, with 100 parts of Intermediate VIII is 47.1, and with 100 parts of Intermediate IX is 92.3. 
     Preferred starting materials that have been used in producing Dyligomers according to the instant invention are named below, their molecular weights and the number of ethylenic double bonds, and of OH groups or of NCO groups per molecule are given parenthetically after their names: 2,4-TDI and 2,6-TDI, (174, 2 NCO groups per molecule, no ethylenic double bond), glycerol (92,3 OH groups per molecule, no ethylenic double bond), ricinoleic acid triglyceride (981.4, 3 OH groups and 3 ethylenic double bonds per molecule). 1,4-butane diol (90.12, 2 OH groups per molecule, no ethylenic double bond), ethylene glycol (62.07, 2 OH groups per molecule, no ethylenic double bond), 173-propane diol (76.1, 2 OH groups per molecule, no ethylenic double bond), but-2-ene-1,4-diol (88.12, 2 OH groups and 1 ethylenic double bond per molecule), 2-butene-1-ol (72.12, 1 OH group and 1 ethylenic double bond per molecule) and sorbitol (182.17, 6 OH groups per molecule, no ethylenic double bond). Hexamethylene diisocyanate (168.21, 2 NCO groups per molecule, no double bond) and 4,4′diphenylmethane diisocyanate (263.54, 2.3 NCO groups per molecule, no ethylenic double bond), can be substituted for the TDI isomer mix. Similarly, other ethylenically unsaturated monomers, e.g., styrene and diallyl phthalate, can be substituted for the triallyl cyanurate in the foregoing intermediate compositions; the amount of the other unsaturated compound should introduce the same number of ethylenic double bonds for a similar polymerized material. The structures of the foregoing starting materials, unless previously set forth, are given below, identified by legends:                         
                           
     Castor oil contains about 85 to 90 percent of ricinoleic acid triglyceride and small amounts of glycerides of other fatty acids, for example, oleic and linoleic, which have the following formulas:                           
     It will be noted that the oleic acid, the linoleic acid, and the other impurities that are normally present in castor oil were not removed before Dyligomer I was produced as described in Example 1. These materials are not detrimental in the final product; indeed, it is not necessary to purify the dilsocyanate, because entirely satisfactory results, in terms of the final product and its properties, can be produced from isomer mixes that are commercially available. Dyligomer I is a liquid in which the constituents of the castor oil in addition to the ricinoleic acid triglyceride and the non-isocyanate constituents of the TDI are soluble. In the Example 1 procedure, assuming that one molecule of TDI reacted with one molecule of ricinoleic acid and one molecule of but-2-ene diol, the amount of TDI charged to the second static mixer in a given unit of time was sufficient only to react with most of the ricinoleic acid triglyceride and of the 1,4-but-2-ene diol charged in that unit of time. As is noted above, however, the reaction product was a homogeneous liquid in which there was no sign of phase separation after prolonged standing. It has been found that a relatively small increase in the proportion of TDI charged to the second static mixer win cause a substantial increase in the viscosity of the reaction product, but that the proportion can be decreased substantially below that charged in the procedure of Example 1 without causing a significant decrease in viscosity. It will be appreciated that the low viscosity of the Example 1 Dyligomer solution is advantageous because it contributes to the effective wetting of fibers. Castor oil and 1,4-but-2-ene diol are immiscible in most proportions, including those in which they were used in the Example 1 procedure. Furthermore, if castor oil, dibutyl tin dilaurate and 1,4-but-2-ene diol are charged in the proportions in which they were used to produce Dyligomer I to a reaction vessel and stirred vigorously while gradual additions of TDI or another dilsocyanate are made until the proportion of diisocyanate used in the Example 1 procedure has been added, reaction proceeds in an uncontrollable manner, and produces a gelatinous mass whose properties vary from batch to batch, and which is probably composed of a solid prepolymer dissolved in unreacted starting materials. However, when 2,4-TDI was added slowly to a vigorously stirred mixture of 930 parts of castor oil and 89 parts of 1,4-but-2-ene diol until a total of 42 parts of TDI had been added, and the dibutyl tin dilaurate was then added, a solution was produced which had about the same viscosity as the Dyligomer I solution of Example I, and was a homogeneous single phase. 
     The solution of Dyligomer I produced as described in Example 1 is effective for introducing both castor oil and 1,4-but-2-ene diol into the intermediate composition produced therefrom as described above. Because castor oil and 1,4-but-2-ene diol are immiscible in the proportions in which they are desired in the intermediate composition, it is not feasible to prepare an intermediate composition from castor oil and 1,4-but-2-ene diol, triallyl cyanurate, benzoyl peroxide, cobalt naphthenate, dimethyl aniline, the DC 193 silicone surfactant, 5 micron calcium carbonate, water and the polymeric colorant, and then to react that intermediate with an appropriately increased amount of a dilsocyanate or of a polyisocyanate. It will be appreciated, however, that the active hydrogen content of the dyligomer solution produced by reacting castor oil and 1,4-but-2-ene diol with 2,4-TDI or with another diisocyanate can vary within rather broad limits. For example, as noted above, ricinoleic acid triglyceride has three OH groups with hydrogens that are at least potentially active and three ethylenic double bonds, while 1,4-but-2-ene diol has two OH groups with active hydrogens and one ethylenic double bond. When the Dyligomer is one produced by the reaction of one molecule of 2,4-TDI with one molecule of ricinoleic acid triglyceride and one molecule of 1,2-but-2-ene diol, the Dyligomer has three active hydrogens (two from the ricinoleic acid triglyceride and one from the 1,4-but-2-ene diol) and four ethylenic double bonds. The reaction of one molecule of an isocyanate with the dyligomer reduces the active hydrogens by one, while the copolymerization of one molecule of a copolymerizable monomer having an ethylenic double bond with one molecule of the dyligomer reduces the number of ethylenic double bonds by one, but produces a group which is capable of further addition polymerization with a copolymenzable monomer having an ethylenic double bond. The amount of a dilsocyanate or of a polisocyanate mixed with the intermediate composition of Example 1, or with another intermediate composition, should introduce from substantially 1.0 to 1.1, most desirably substantially 1.05 NCO groups per active hydrogen in the intermediate composition that is capable of reacting with an NCO group of the diisocyanate or polyisocyanate. 
     Diisocyanates other than 2,4-TDI form products analogous to that shown above for the several Dyligomers, except for the positions, numbers, or both of the urethane groups. For example, 2,4,6-toluene trijsocyanate would produce a product with a third urethane group, while a monoisocyanate would produce a product with only one urethane group, and the other diisocyanates would produce products where the position of at least one of the urethanes is different. Dyligomer III is the compound that is produced when castor oil, 2,4-TDI and 1,4-butane diol are reacted in such proportions that, for every three OH groups in the castor oil, there are two NCO groups in the dilsocyanate and two OH groups from the 1,4-butane diol. The following dyligomer can also be produced from castor oil, 2,6-TDI and 1,4-butane diol:                           
     Dyligomer I has a certain capability for reaction with an isocyanate to produce a structure in which moieties derived from the dyligomer are linked to one another through urethane groups and chains formed by the polycondensation of the dyligomer with at least one polyisocyanate, and a certain capability for reaction with a copolymerizable monomer in which the moieties are also linked to one another, but by chains formed by the addition polymerization of ethylenic double bonds of the dyligomer with ethylenic double bonds of the copolymerizable monomer. The OH group of the moiety derived from the 1,4-but-2-ene-diol reacts with an isocyanate more readily than do the OH groups derived from the ricinoleic acid triglyceride; similarly, the ethylenic double bond of the moiety derived from the 1,4-but-2-ene diol reacts with an ethylenic double bond of a copolymerizable monomer more readily than do the ethylenic double bonds of the moiety derived from the ricinoleic acid triglyceride. It will be appreciated, therefore, that the reactivity of a dyligomer produced from castor oil, 1,4but-2-ene diol and 2,4TDI varies as a direct function of the ratio of 1,4but-2-ene diol to castor oil It will also be appreciated that Dyligomer II, because it has one more OH group and one fewer double bond per molecule than Dyligomer I, has a greater capability for reaction with a polyisocyanate and a lesser capability of addition copolymerization. Dyligomers III and W have the same capability as Dyligomer H for addition copolymerization, and progressively less capability for reaction with a polyisocyanate. By using two or more of the dyligomers in an intermediate composition, it is possible to control the capability of the intermediate for reaction with a polyisocyanate and for addition copolymerization as desired. 
     Another structure member according to the invention is indicated generally at  31  in FIG.  9 . The member  31  can be produced in the mold  14  of FIGS. 2-5, appropriately sized, by placing a piece of the aluminum floor  19  in the mold, introducing the desired amount of a foamable composition, e.g., that of Example 1, into the floor  19 , placing a second piece  32  of a different aluminum floor on top of the foamable composition, positioned as show in FIG. 9, closing the lid of the mold, and clamping the lid shut. It may be desirable, in producing the member  31 , for one end of the floor  19  (and of the floor  32 ) to be higher than the other so that entrapped air, if there is any, can escape from the higher ends of alternate ones of the channels of the floor  32  as the foaming composition moves upwardly. The floor  32  has a plurality of parallel longitudinally-extending channels adjacent ones of which have common sidewalls  33  and webs  34  and  35  which are at opposite ends of the sidewalls  33 . 
     Still another structural member is indicated generally at  36  in FIG.  10 . The member  36  can be produced in the mold  14  of FIGS. 2-5, appropriately sized, by placing a piece of the aluminum floor  19  in the mold, introducing the desired amount of a foamable composition, e.g., that of Example 1, into the floor  19 , placing a second piece of a different aluminum floor (not illustrated) on top of the foamable composition, inserting a filler (e.g., an appropriately sized piece of plywood) over the second piece of floor, closing the mold lid, and clamping it in place. The second piece of aluminum floor must have such a configuration that it forms the upper surface of the foamable composition as it expands into contact with the second floor to the shape shown in FIG. 10 for a body  37  of a foamed material, and must be protected, e.g., by a thin sheet of polyethylene, so that it does not adhere to the foam  37 . The second piece of a aluminum floor is then removed from the mold; a second foamable composition is poured over the body  37  of foam; and a third piece, designated  38  in FIG. 10, of aluminum floor is positioned over the second foamable composition, positioned as shown. A filler, if necessary, is then placed in the mold, over the floor  38 , and the lid is closed and clamped. The sizes of the channels in the floors  19  and  38  can be varied as desired, and the floor  38  can be positioned as shown, so that its channels are parallel to the channels in the floor  19 , or it can be positioned so that its channels extend at any desired angle to the channels in the floor  19 . When the channels are parallel as shown in FIG. 10, the floor  19  and the floor  38  both increase the strength of the structure mainly when it is supported on members that extend laterally of the channels of the floors. However, when the channels of the floor  38  extend at right angles to the channels of the floor  19 , the former increase the strength of the structure when it is supported on members which extend parallel to the channels of the floor  19  while the latter increase the strength when the structure is supported on members which extend laterally of the channels of the floor  19 ; this is often a desirable arrangement. 
     Two steps in the production of still another structural member, designated  39  in FIG. 14, are shown in FIGS. 11,  12  and  13 . The structural member  39  is made up of a floor  40  having channels  41  which run at a right angle to the paper in FIGS. 11 and 12 and a second floor  42  having channels  43  which run parallel to the paper in FIG.  12  and at right angles in FIG.  13 . The structural member  39  can be produced in a mold  44  having a bottom  45 , sides  46 , a top  47  and end walls (not illustrated). The steps carried out in producing the member  44  involve placing the aluminum floor  40  on the bottom of the mold  44 , introducing a foamable composition  48  into the mold  44  on top of the floor  40 , placing the aluminum floor  42  on top of the foamable composition, and placing a sheet  49  of plywood on top of the floor  42 . The assembly which results is shown in FIG.  11 . The top  47  of the mold  44  is ten closed; the foamable composition  48  expands, forcing the plywood sheet against the top  47  of the mold  44 , and undergoes partial cure. The assembly at this stage is shown in FIGS. 12 and 13, where the partially cured foam is designated  50 . The foamable composition can be that described in Example 1, and it can be introduced into the mold  44  at the rate of 568 g of the composition per 929 cm 2  of upper surface of webs  51  and  52  of the aluminum floor  40 . It is desirable for one of the sides  46  of the mold  44  to be raised above the other during this part of the operation so that air in the channels  43  can flow ahead of the rising foam to one end or the other of the floor  42  and can escape from the channels  43  and from the mold  46 , which is highly previous to air. The lid  47  of the mold  44  is then raised to the position shown in FIG. 11, and the sheet  49  of plywood is removed from the mold  44 . A foamable composition which can be the same as that described in Example 1, is then introduced into the mold  44  on top of the floor  42  at the rate of 568 g of the composition per 929 cm 2  of upper surface of webs  53  and  54  of the aluminum floor  42 . The lid  47  of the mold  44  is then closed again; the foamable composition expands against the lid  47  of the mold  44 , and undergoes partial cures. The assembly, which now has its final configuration is shown in FIG. 14, where the partially cured foam above the floor  42  is designated  56 . 
     It has been demonstrated, by data presented above, that there is cooperation between a thermoset urethane foam and an aluminum floor with which the foam is in intimate contact, and to which it is tightly bonded. The data involve an aluminum floor which had such thin walls that, when it was suspended between two supports which extended transversely of its channels, and were separated from one another by seven inches, a load applied in the center of the member caused it to collapse before available instrumentation indicated the magnitude of the load. Another structure, in which the same aluminum floor was in intimate contact with, and tightly bonded to, a thermoset urethane foam, when subjected to the same test withstood an applied load of 4650 pounds before failure, while the foam itself separately produced, failed under a load of only 700 pounds. The foam itself had essentially the configuration of a body  74  of thermoset urethane foam (FIG. 6) in a structural member according to the invention, while the structure in which the aluminum floor was in intimate contact with, and tightly bonded to, a thermoset urethane foam, had essentially the configuration of the FIG. 6 member, except that there was no expanded polystyrene sheet  13 , and there was no pad  21 . 
     It will be appreciated that the cooperation between the floor and the thermoset urethane which is discussed in the preceding paragraph is particularly effective when the article tested is supported as described on members which extend transversely of the channels. The structural member  56  (FIG. 14) is particularly advantageous because it has aluminum floors  40  and  42 , which extend essentially at right angles to one another. As a consequence, the load required to cause failure is essentially independent of the angle of the supports to the structural member, and a substantial overhang beyond a support in any direction relative to the floor is acceptable. 
     A fragment of another structural member according to the invention is designated generally at  56  in FIG. 15, where it is shown in a mold having a bottom  57  and a top  58 . The member  56  is composed of a thermoset urethane or other foam  59  disposed between sheet members indicated generally at  60  and  61 . The sheet members  60  and  61  have been produced on a brake from galvanized sheet steel about 0.03 mm thick. The sheet steel is broken about every 30 mm to produce a plurality of legs  62 , each of which extends across the sheet at about 90° thereto and is about 30 mm long and a plurality of second legs  63 , each of which extends across the sheet at about 180° to one of the legs  62  back to the original plane of the sheet, so that the members have a plurality of substantially coplanar strips  64  with legs  62  and  63  between adjacent strips  64 . The structural member  56  can be produced in a suitable mold, e.g., identical to that designated  44  in FIG. 11, and having the bottom  57  and the lid  58 , by placing the sheet member  60  on the bottom  27  of the mold, with the legs  62  and  63  extending upwardly, introducing a foamable thermosetting composition, e.g., the foamable urethane composition described in Example 1, into the mold on top of the member  60 , placing the member  61  on top of the foamable composition, with the legs  62  and  63  extending downwardly, and closing the lid  58 . The foamable composition expands and cures to a thermoset condition having the shape shown in FIG. 15, and the foam and the sheet members  60  and  61  are confined in the mold during cure so that the cured foam is tightly adhered to the sheet members  60  and  61 . 
     It will be appreciated from the foregoing discussion that a structural member similar to that designated  56  in FIG. 15, but differing therefrom in that the legs  62  and  63  are not parallel to one another is a preferred structural member according to the instant invention because the load required to cause failure thereof is independent of the direction in which supports extend. 
     Still another structural member according to the invention is shown in horizontal section in FIG. 16, where it is indicated generally at  65 . As shown in FIG. 16, the structural member  65 , which is made up of a body  66  of a thermoset foam which is tightly adhered to a longitudinal extending metal reinforcement  67 , is in a split, cylindrical mold  68 , in which it can be produced. The mold  68  is composed of two mold halves  69  and  70  which abut along mating lines  71  and  72 , and can be attached to one another in any suitable manner, as by straps or locks (not illustrated). The metal reinforcement  67  can be produced by bending a sheet member  60  (FIG. 15) so that a plurality of the planar strips  64  form a cylinder with the legs  62  and  63  extending generally radially outwardly from the cylinder. It is not necessary that the ends of the sheet member be fastened together, so long as the metal is deformed sufficiently that it will remain in the cylindrical shape for a short period of time until it is locked in position by the body  66  of thermoset foam. 
     The structural member  65  can be produced by placing a polyethylene sleeve  73  inside the mold half  69 , mating the mold half  70  with the mold half  69 , with the sleeve inside, fastening the two mold halves together, supporting the mold in a vertical position with a suitable base material thereunder, e.g., a sheet of polyethylene, introducing a quantity of a foamable, thermosetable material e.g., the polyol-diisocyanate material of Example 1, into the sleeve  73 , lowering the metal reinforcement  67  to the desired vertical position in the mold, supporting the reinforcement at the desired vertical position, e.g., on small wires, and, if necessary, placing a cover on the top of the mold  68 . Pins (not illustrated) can also be used to position the metal reinforcement  67  relative to the inner surfaces of the mold halves  69  and  70 . The pins if used, can merely be cut from the exterior of the final post. 
     In a typical example, the mold  68  has an internal diameter of 4 inches (4.16 cm) and is 7 feet (213.4 cm) long while the metal reinforcement  67  is composed of galvanized steel sheet 0.010 inch (0.254 mm) thick, the straps  64  are about one inch (2.54 cm) wide, the legs  62  and  63  extend outwardly from the cylindrical surface about one inch (2.54 cm), the longitudinal length of the reinforcement  67  is about three feet (91.4 cm), and the reinforcement  67  is supported about one foot (30.5 cm) above the bottom of the mold  68  so that its top is about three feet (91.4 cm) below the top of the mold. A charge of the diisocyanate-polyol of Example 1 sufficient to produce a cured urethane foam having an apparent density ranging from about 20 to about 30 pounds per cubic foot (0.32 to 0.48 g per m 3 ), in this case, produces a structural member that is admirably suited to serve as a fence post. The reinforcement strengthens the post in the region where breaking usually occurs; the urethra is not attacked by insects. A structural member similar to the member  65 , differing only in that it is square or rectangular in cross section and in that the reinforcement extends to within about 6 inches (15 cm) from each end is admirably suited for use as a utility pole cross arm. Such a member can be produced by the method described above for the production of the member  65 , but using a mold having a square or rectangular cross section and metallic reinforcement of a suitable length. 
     The best structural member presently contemplated for use as a floor for a truck or trailer is indicated generally at  75  in FIGS. 18 and 19. The member  75  has a sheet member  76  similar to those designated  60  and  61  in FIG.  15 . Referring again to FIGS. 18 and 19, the sheet member  76  has a plurality of legs  77 , each of which extends across the sheet member  76  at about 90° to the paper in FIG.  18  and is about 30 mm high and a plurality of second legs  78 , each of which extends across the sheet member at about 180° to one of the legs  77  back to the original plane of the sheet, so that the members have a plurality of substantially coplanar strips  79  with legs  77  and  78  between adjacent ones of the strips  79 . The sheet member  76  also has a plurality of channels  80 , each of which is composed of a web  81  and sidewalls  82 . The structural member  75  is designed for use as a floor for a refrigerated truck or trailer with floor supports (not illustrated) which extend across the truck or trader at various points. The channels  80  of the member  75  are spaced from one another so that the webs  81  of different ones of the channels  80  rest on different ones of the floor supports of the truck or trailer, and can be attached thereto by screws which are turned into a foam  83  which is in intimate contact with and firmly bonded to the sheet member  76 . 
     The structural member  75  also has an aluminum floor indicated generally at  84  which is in intimate contact with and fly bonded to the foam  83 . The aluminum floor  84  has a plurality of coplanar strips  85  (FIG. 19) and channels  86  formed by webs  87  and sidewalls  88 . The channels  86  extend parallel to the paper in FIG. 18, and at 90° to the paper in FIG.  19 . The member  75  can be produced as previously described. 
     A mold indicated generally at  89  in FIGS. 20,  21  and  22  has a bottom  90 , two side walls  91  and  92 , and an end wall  93  (FIG.  20 ). The mold  89  is shown in FIG. 21 with a top  94  resting on the sidewalls  91  and  92 . A projecting member  95 , which is integral with the top  94 , extends substantially to the bottom  90  of the mold  87 , filling about ¾ of the space between the top  94  and the bottom  90 . To produce a part in the mold  89 , a polyethylene tube (not illustrated) was placed on the bottom  90  of the mold so that its edges extended beyond the side walls  91  and  92 , one end extended beyond the end wall  93 , and the other end extended beyond a front end  96  of the bottom  90 . The top  94  was then placed over the polyethylene tube in the position shown in FIG. 21, and clamped in place; the mold  89  was rotated  90  so that the end wall  93  was down and the front end  96  of the mold was up; and the mixture of MDI and the intermediate composition described in Example 1 was introduced into a cavity  97  (FIG. 21) inside the polyethylene tube until the mixture reached the top of the mold. The mold was then rotated 90° so that the bottom  90  was down; the top  94  was removed, and a top  98  (FIG. 22) was clamped to the mold  89  to form a cavity  99  which was rectangular in cross section, and about ½ inch by 2 inches by 8 feet. The mixture of MDI and the intermediate composition foamed to fill the cavity  99  and cured After about 10 minutes, the top  98  was removed from the mold, and a strip of cured material was recovered. The cured material was extremely flexible when it was removed from the mold; it was bent so that the 2 inch faces of the two ends were parallel to one another and there was an arcuate portion between the ends which had a radius of about 18 inches. The strip was supported in this shape for 48 hours, and was then examined. It was no longer flexible; it resisted bending from the shape to which it had been formed, with the ends parallel and an arcuate portion between, and showed elastic properties after deformation. 
     It will be appreciated that the phenomena described above indicate that, within ten minutes after the mixture of MDI and the intermediate composition was introduced into the mold  89 , a polymer having a molecule in which the moieties derived from the dyligomer were linked to one another through urethane groups and chains formed by the polycondensation of the dyligomer with the polyisocyanate, and, during the next 48 hours, additional chains were formed by the addition polymerization of ethylenic double bonds of the dyligomer with ethylenic double bonds of the triallyl cyanurate. It will also be appreciated that the intermediate of Example 1 contained the reactants which underwent addition polymerization, benzoyl peroxide as a free radical catalyst and cobalt naphthenate as an initiator and that, since the composition was stable at ambient temperature of about 25° C. for extended periods of time, that the proportions of benzoyl peroxide and of cobalt naphthenate present were insufficient to initiate addition polymerization at ambient temperature. However, the exotherm from the isocyanate condensation raised the temperature of the composition enough that the addition polymerization occurred after the isocyanate condensation. This combination of properties is an important characteristic of the intermediate composition of Example 1, and of other intermediate compositions according to the invention. 
     A window frame according to the invention is indicated generally at  100  in FIG.  23 . The frame  100  is composed of side guides  101  and  102 , an upper stop  103  and a sill  104 . The side guides  101  and  102  are composed of channel members indicated generally at  105  (FIG. 24) bonded to bodies  106  of polymeric material preferably according to the invention, while the sill  104  is composed of a body  107  of the polymeric material, preferably according to the invention (FIG.  25 ). The upper stop  103  has the same structure as the side guides  101  and  102 , but the body of the polymeric material that is bonded to the channel  105  thereof is not illustrated. The channel members  105  are preferably extruded aluminum or vinyl shapes. The bodies  106  and  107  of the polymeric material are bonded to or integral with one another and are bonded to or integral with the body of the polymeric material that is bonded to the channel  105  of the stop  103  so that the frame  100  has structural integrity. The channel members  105 , as shown in FIG. 24, have flat faces  108  and three channels having webs  109  and sidewalls  110 . 
     The window frame  100  can be produced in a mold indicated generally at  111  in FIG.  26 . The mold  111  comprises a core  112  to which three lengths of channel member  105  are releasably attached, as by a pressure sensitive adhesive (not illustrated). As can be seen better in FIG. 27, the mold  111  also includes side members  113  and  114  which are spaced from the core  112  so that there are cavities between one of the channel members  105  and the side member  113  and between the other of the channel members  105  and the side member  114 . There is a sir cavity (not illustrated) between a top member  115  (FIG. 26) of the mold  111  and the channel  105  which extends across the top of the core  112  between the side members  113  and  114 . As shown in FIG. 26, there is a sill filler  116  which has the shape of the sill  104  and is positioned in the bottom portion of the mold  111  where it extends between the side members  113  and  114  and between the bottom of the core  112  and a bottom mold member  117 , closing the ends of the cavities between the channel members  105  and the side members  113  and  114 . 
     Before a window frame is produced in the mold  111 , the surfaces of the mold that will contact the material from which the frame is to be produced are sprayed with the previously described 5 percent solution in naphtha of a silicone caulking material and cellophane tape is adhered with a pressure sensitive adhesive over small openings (e.g., the undersides of joints  118  between adjacent ones of the channels  105 ) through which the material might otherwise escape. A curable material is then introduced into the cavities between the channel members  105  and the side members  113  and  114  and the top member  115 . A polyester or an epoxy casting resin can be used to produce the window frame  100 , in which case the casting resin is merely poured into the indicated cavities until they are filled or nearly filled, and allowed to cure. The best material presently contemplated for use in producing the fine  100  is a polymerizable composition according to the instant invention, most desirably one produced by mixing, as described above, 100 parts of Intermediate composition VII, supra, and 47.1 parts of the previously identified, solubilized MDI, and introducing the polymerizable composition which results into the cavities of the mold in the proportion of 0.58 g per cubic centimeter of cavity. If a heavier window fame is desired, a greater proportion of the polymerizable composition can be introduced into the mold cavity and a cover can then be placed over the mold cavity to prevent the escape of the composition therefrom. 
     The procedure just described produces most of the window frame  100 , but without the sill  104 . About 5 minutes after the polymerizable composition according to the invention was introduced into the mold  111 , the sill filler  116  can be removed from the mold, and replaced by a mold part, preferably one which can be closed, of suitable shape to form the sill  104 . A new charge of the same or a different polymerizable composition can then be prepared and introduced into the mold part in an amount slightly in excess of that required to fill the mold part; the mold part can then be closed, and the polymerizable composition will force itself into contact with the previously formed frame part. It has been found that a window frame  100  having a strength substantially in excess of that required can be produced in this way. 
     A fragment of a stud wall is shown in FIG. 28 with the window frame  100  installed between adjacent studs  119 , which can be studs in the regular stud pattern in a building (not illustrated) of which they are a part, or can be specially installed at a location where a window to be carried by the frame  100  is required. The side members  113  and  114  can merely be attached, e.g., by a screw or a nail, to one of the studs  119 . The frame  100  can then be shimmed as required, and additional fasteners can be inserted into the studs and the frame  100  to mount the frame in a vertical position. Headers  120  and  121  can then be installed above and below the frame  100  to carry studs  122  and  123 , as required. The frame  100  can be nailed or otherwise attached to the headers  120  and  121 , if desired. 
     Ultimately, a window sash (not illustrated) in its own frame can be installed in the frame  100 . The window sash can be a double hung, casement, awning, slider or the like unit, which can have a channel across its top and opposed channels at its edges, all of which are sized to be received in one of the channels of the members  105 , between the sidewalls  110 , and one of the side channels can be movable between an extended position and a retracted position in which the window can be advanced into the frame  100  so that the other side channel and the top channel are received between opposed ones of the sidewalls  110  of the frame  100 . With the movable channel in the retracted position, the window frame is advanced into the frame  100  until the other side channel and the top channel are received as just described, and the movable channel is moved to its extended position between opposed sidewalls  110 , which then prevent removal of the window frame from the frame  110  so long as the movable channel is in its extended position. 
     A wall panel according to another aspect of the instant invention is indicated generally at  124  in FIG.  29 . The panel  124 , in a typical example, can be 4 feet by eight feet, and 4 inches thick. As can be seen in the upper right hand portion thereof where a corner of the panel  124  has been broken away, the panel  124  has a central core  125  which can be a thermoset, cellular, urethane which is chemically bonded to an end wall  126 , a front wall  127 , a top wall  128  and a rear wall  129 . The core  125  is also chemically bonded to an end wall  130  and to a bottom wall  131 . The walls  126  through  131  are all composed of a cured cement. 
     The wall panel  124  can be produced by first casting the front wall  127  in a suitable mold, positioning a second mold relative to the cast front wall, casting the end walls  126  and  130  and the top and bottom walls  128  and  131  in the second mold so that they are in contact with the previously cast front wall, casting the rear wall  129  in a suitable mold, and positioning the free edges of the end walls  126  and  130  and of the top and bottom walls  128  and  131  so that they are in contact with the edges of the previously cast rear wall  129  to produce a cement shell  132  having the walls  126  through  131 . The top wall  128  terminates about 2 inches short of the end wall  130 . In the panel  124 , the central core  125  fills the shell  132 , which is hollow, including the space between the end of the top wall  128  and the end wall  130 . As a final step in producing the panel  124 , after the shell  132  has cured sufficiently, a suitable composition is introduced into the interior of the shell  132  to form the core  125 , which is a cellular, cured, thermoset urethane. 
     A suitable mold in which the front wall  127  can be cast is indicated generally at  133  in FIG.  30 . The mold  133  is merely a sheet  134  of plywood having a flat upper surface  135  and wooden strips  136 ,  137 ,  138  and  139  attached to the surface  135  to form a topless mold of rectangular shape which is 4 feet by 8 feet and ¼ inch thick. The front wall  127  can merely be cast in the mold  133 , or suitable reinforcement (not illustrated) can be placed in the mold before the wall is cast. The reinforcement can be flat, so that it is imbedded in the wall  127 , or it can also have a portion or portions extending beyond the ultimate surface of the wall  127  to reinforce the core  125  (FIG. 29) when it is ultimately formed. Two walls  140  are shown in FIG. 31 with reinforcement  141  extending outwardly from major surfaces thereof. 
     One of the walls  140  (FIG. 31) is shown in FIG. 32, where it constitutes the bottom of a mold which is composed of an outer mold portion  142  and an inner mold portion  143 . A cement is cast into a space between the outer and inner mold portions  142  and  143  to form the walls  126 ,  128 ,  130  and  131 , which are shown in FIG. 32 in the mold. To complete the shell  132 , the inner mold portion  143  is lifted to separate it from the walls  126 ,  128 ,  130  and  131 , and the remaining assembly is inverted, and placed on a mold  133  (FIG. 30) into which a cement has been cast to the level of the tops of the strips  136 ,  137 ,  138  and  139 . Plywood sheets  144 ,  145 ,  146  and  147 , which constitute the outer mold portion  142 , rest on the strips  136 ,  137 ,  138  and  139  when the assembly of FIG. 32 is placed on the mold  132 , and surfaces  148 ,  149 ,  150  and  151  of the walls  126 ,  128 ,  130  and  131  are in contact with the cement which had been cast into the mold  133 . When this cement cures sufficiently, the outer mold portion  142  can be lifted from the shell  132 , and the shell can be lifted from the mold  133 . 
     At this stage the shell  132  has been produced, and has a hollow interior. The shell has front and rear walls  127  and  129  which are 4 feet by 8 feet and ¼ inch thick, end walls  126  and  128  which are 4 feet by 4 inches and ¼ inch thick, a top wall  128  which is 7 feet 10 inches by 4 inches and ¼ inch thick, and a bottom wall  131  which is 8 feet by 4 inches and ¼ inch thick. The wall panel  124  is then completed by introducing a composition into the space between the end of the top wall  128  and the end  130  in an amount sufficient to form a cured urethane core which fills the interior of the shell  132  and is chemically bonded to the walls of the shell  132 . 
     The cement that is used to produce the shell  132 , as described above, can be a mixture of 70 parts Type 1 hydraulic cement, 15 parts “2 mil” calcium carbonate, 15 parts “10 mil” calcium carbonate, ½ part calcium oxide, and 100 parts water. 
     Another cement that is used to produce the shell  132  can be a mixture of 70 parts Type 1 hydraulic cement, 10 parts “2 mil” calcium carbonate, 10 parts “10 mil” calcium carbonate, 100 parts ceramic microspheres, and sufficient water to provide a desired consistency for working. Ceramic microspheres which are commercially available from Minnesota Mining and Manufacturing under the designation G3500 have been used; these microspheres range in diameter from 105 to 155 μm, and have a surface area of 0.08 m 2 .cc −1 . Ceramic microspheres which are commercially available from Fillite USA, Inc., Huntington, W.V., under the designations “Fillite 52/7/5” and “Fillite 200/7” have also been used. 
     It is often desirable to accelerate the initial rate of hydration of the hydraulic cements in compositions identified in the two preceding paragraphs so that parts of structures according to the instant invention which are produced therefrom harden more rapidly, and, as a consequence, can be handled sooner after they are formed. Wheat flour can be added to the compositions to cause such acceleration. For example, from 1 to 20 parts of wheat flour, preferably from 5 to 15 parts and, most desirably, about 10 parts, can be added to either of the compositions identified in the indicated paragraphs. 
     The composition that is introduced into the shell  132  to produce the urethane core can be produced from an intermediate composition and a liquified MDI. The intermediate composition can be produced from “Dyligomer I” whose production is described above, by thorough mixing of 100 parts of the Dyligomer I solution, 28.1 parts of triallyl cyanurate, 1 part of benzoyl peroxide, 1.5 parts of cobalt naphthenate, 1 part of dimethyl aniline, 1.2 parts of a silicone surfactant that is commercially available from Dow Corning under the designation DC 193, 90 parts of 5 micron calcium carbonate (325 mesh), 0.5 part of water and 1 part of a polymeric colorant. 
     The composition that is introduced into the space between the end of the top wall  128  and the end wall  130  to form a cured urethane core which fills the interior of the shell  132  can be a mixture of the intermediate composition and a liquified MDI. The mixture of the liquefied 4,4′-MDI and the intermediate composition of Example 1 was produced in the apparatus of FIG.  33 . The MDI was charged to a vessel  152  (FIG.  33 ), and the intermediate composition was charged to a vessel  153 . The MDI was then pumped from the vessel  152  through a line  154  to a meter  155 , while the composition in the vessel  153  was pumped from the vessel  153  through a line  156  to the meter  155 , which was set to deliver the MDI at a rate of 44.6 parts per minute and the intermediate composition in the vessel  153  at a rate of 1 parts per minute through a line  157  to a mixer  158  where they were rapidly and thoroughly mixed before being discharged through a line  159  into the shell  132 . The MDI introduced into the line  159  contained substantially 1.05 NCO groups per OH group in the intermediate composition introduced into the line  159 . A charge of 112 pounds of the mixture into the cement shell  132 , when it has the dimensions set forth above, produces a core having an apparent density of 12 pounds per cubic foot. 
     In another aspect, the invention is a wall structure which can be assembled from especially fabricated blocks, one of which, designated generally at  160 , is shown in FIGS. 34 and 35. A fragment of the wall structure is indicated generally at  161  in FIG.  36 . The fragment  161  of the wall structure comprises parts of first, second and third courses composed, respectively, of blocks  160 - 1 , of blocks  160 - 2  and  162 - 2 , and of blocks  160 - 3 . Ends  163  of the blocks  160  (FIG. 34) have tongues  164  which are received in grooves  165  (FIG. 35) in ends  166  of adjacent blocks  160  to prevent lateral movement of each block relative to the adjacent block or relative to each adjacent block, as the case may be. As shown in FIG. 36, the blocks  160 - 1  of the first course are mounted on a foundation  167 , while the blocks  160 - 2  and  162 - 2  of the second course are mounted on the blocks  160 - 1 , and the block  160 - 3  of the third course is mounted on the blocks  160 - 2  and  162 - 2 . The blocks  160 - 1 ,  160 - 2  and  160 - 3  are alike; their major surfaces, in the structure shown, are 1 foot by 2 feet, while the major surface of the block  162 - 2  is 1 foot by one foot. 
     Referring to FIGS. 34 and 35, there are longitudinally extending recesses  168  and  169  in tops  170  of the blocks  160 . The recess  168  is continuous around the block  160 , continuing in the ends  163  and  166 , and in a bottom  171  thereof. The recess  169 , on the other hand, extends longitudinally of the top  170  and of the bottom  171 , but terminates short of the tongue  164  of the end  163  and of the recess  165  of the end  166 . There are also recesses  172  in the tops  170  of the blocks  160  and recesses (not illustrated) in the bottoms  171  which are aligned in the wall structure so that splines received therein are also received in the recesses  172  and, as a consequence, lock blocks  160  against sliding movement relative to blocks thereabove or therebelow, as the case may be. 
     As best seen in FIG. 36, a spline  173  is attached by bolts  174  to the foundation  167 . The spline  173  extends under all of the blocks of the first course, and is received in the recesses  169  (FIGS. 34 and 35) in the bottoms of the blocks  160  of the first course. As is indicated by a section of the spline  173  at the left in FIG. 36, additional spline sections are attached to the foundation  167  for the entire length of the wall of which the fragment  161  is a part. A spline  175  (FIG. 36) is received in the longitudinally extending recesses  169  (FIGS. 34 and 35) in the tops of the blocks of the first course and in the bottoms of the blocks of the second course, and splines  176  and  177 , two of which are shown in FIG. 36, are received in the recesses  169  (FIGS. 34 and 35) in the tops of the blocks of the second and third courses and in the bottoms of the blocks of the third and fourth courses. The splines  173 ,  175 ,  176  and  177  lock the blocks into which they are received against lateral movement relative to the foundation  163  or relative to adjacent blocks thereabove or therebelow, as the case may be, while splines  178  received in the openings  172  (FIGS. 34 and 35) and in aligned openings in the bottoms  171  of the blocks, as described above, lock the blocks into which they are received against longitudinal movement relative to the foundation  167  or relative to adjacent blocks thereabove or therebelow, as the case may be. 
     The structure of FIG. 36 also includes stepped rods, one of which, designated  179 , is shown in an exploded position. The rod  179  can be assembled with the front of a wall shown in FIG. 36, by inserting an end  180  thereof into recesses  168  in the ends  163  and  166  of adjacent blocks  160  as indicated by an arrow  181  and bringing bends  182 ,  183  and  184  in the rod  179  into contact with stepped portions of the structure as indicated by arrows  185 ,  186  and  187 . In a preferred embodiment, the stepped  179  is placed in the position just described before the block  160 - 1  to the left of the arrow  181  is added to the structure, and its bottom end is bolted or otherwise attached to the foundation  167  so that it prevents upward vertical movement of the blocks which are below its horizontal portions. 
     There is preferably a cap member on the top course of the wall of FIG. 36, and the cap member is preferably anchored to the wall therebelow, and to a roof thereabove. Such a cap member is shown in FIG. 38, designated  188 . The member  188  is on the tops  170  of the blocks, which are designated  160 - 9 , of the top course of the wall. It has a web  189  which extends across the recesses  168  in the tops  170  and an integral sidewall  190  which extends downwardly adjacent a major surface  191  of the blocks  160 - 9 . There are openings  192  in the web  189  of the cap member  188  from which locks  193  extend horizontally to prevent the cap member  188  and the blocks  160  therebelow from moving upwardly from the positions shown. The locks  193  are terminal portions of the rods  179  (FIG. 36) which, as previously explained, have bottom ends which are preferably bolted or otherwise attached to the foundation  167  to prevent upward vertical movement. A roof not shown in FIG. 38, can, in be bolted or otherwise attached to the cap member  188 , so that the entire structure is anchored to the foundation. 
     The cap member  188  can also be attached to the wall therebelow by bolts (not illustrated) which extend downwardly through the recesses  168  (FIG. 34) in the ends of adjacent blocks  160  in the top course of blocks, and are, in turn, bolted or otherwise attached to stepped rods between the top course of blocks and the course therebelow. Special blocks (shown in FIGS. 49 and 50) can also be used, as subsequently described, to construct the top course of the structure of the invention. 
     It will be appreciated that all of the blocks designated “ 160 ” have the structure shown in FIGS. 34 and 35 and that the course in which those blocks appear in the structures of FIGS. 36 and 38 are, indicated by numbers which follow “ 160 .” and a dash. Thus, blocks designated “ 160 - 1 ” are in the first course; “ 160 - 2 ” in the second course, etc. The block designated  162 - 2  (FIG. 36) is functionally equivalent to the block  160 , differing only in the dimensions of its major surfaces, as set forth above. One of the blocks  162  is shown in FIGS. 39 and 40. Ends  194  of the blocks  162  (FIG. 39) have tongues  195  which are received in the grooves  165  of the blocks  160  (FIG. 35) or in grooves  196  (FIG. 40) in ends  197  of the blocks  162  to prevent lateral movement of each block relative to the adjacent block or relative to each adjacent block, as the case may be. 
     Referring to FIGS. 39 and 40, there are longitudinally extending recesses  198  and  199  in tops  200  of the blocks  162 . The recess  198  is continuous around the block  162 , continuing in the ends  194  and  197 , and in a bottom  201  thereof. The recess  199 , on the other hand, extends longitudinally of the top  200  and of the bottom  201 , but terminates short of the tongue  195  of the end  194  and of the recess  196  of the end  197 . There are also recesses  202  in the tops  200  of the blocks  162  and recesses (not illustrated) in the bottoms  201  which are aligned in the wall structure so that splines received therein are also received in the recesses  202  and, as a consequence, lock blocks  162  against sliding movement relative to blocks thereabove or therebelow, as the case may be. 
     It will be appreciated that the agent  161  of wall shown in FIG. 36 has an end on the right which composed of a plurality of ends  166  of the blocks  160  and of ends  197  of the blocks  162 , and, when completed, would have an end on the left composed of a plurality of ends  163  of the blocks  160  and  194  of the blocks  162 . These wall ends can be subjected to a manual fishing operation to provide a smooth surface of a desired configuration An intersecting wall, if desired, can be constructed in the same manner used to construct the wall  161  (FIG. 36) on a foundation having the desired positional relationship with the wall  161 . In a like way, the intersection between the two walls can be subjected to a manual finishing operation to provide the desired surfaces. 
     In a preferred embodiment, blocks indicated generally at  203  and  204  in FIGS. 41 and 42 can be used with the blocks  160  to produce structures comprising two walls which intersect at right angles. The blocks  203  have two body parts, designated  205  and  206 , which extend longitudinally in two different regions which are at right angles to one another. There are longitudinally extending recesses  207  and  208  in tops  209  of the parts  205  of the blocks  203 . The recesses  208  continue in ends  210 , and in bottoms (not illustrated) of the parts  205 . The recesses  207 , on the other hand, extend longitudinally of the tops  209  and of the bottoms (not illustrated) but terminate short of tongues  211  of the ends  210 . There are also longitudinally extending recesses  212  and  213  in tops  214  of the parts  206  of the blocks  203 . The recesses  213  continue in ends  215  and in bottoms (not illustrated) of the parts  206  of the blocks  203 , while there are recesses  213  in the bottoms (not illustrated) of the parts  206 , but these recesses terminate short of grooves  216  in the ends  215 . 
     The blocks  204  (FIG. 42) also have two body parts, designated  217  and  218 , which extend longitudinally in two different directions which are at right angles to one-another. There are longitudinally extending recesses  219  and  220  in tops  221  of the parts  217 . The recesses  219  continue ends  222  and in bottoms (not illustrated) of the parts  217 . The recesses  220 , on the other hand, extend longitudinally of the tops  221  and of the bottoms (not illustrated) but terminate short of tongues  223  of the ends  222 . There are also longitudinally extending recesses  224  and  225  in tops  226  of the parts  218  of the blocks  204 . The recesses  224  continue in ends  227  and in bottoms (not illustrated) of the parts  218  of the blocks  204 , while the recesses  225  continue in the bottoms (not illustrated) of the parts  218 , but terminate short of grooves  228  in the ends  227 . 
     To produce a structure comprising two walls which intersect at right angles using the blocks  160  of FIGS. 34 and 35 and the blocks  203  and  204  of FIGS. 41 and 42, splines  229  and  230  (FIG. 43) are bolted or otherwise attached to a foundation  231  which has a horizontal upper surface. The splines  229  and  230  are positioned so that, when the former is received in the longitudinally extending recess  212  in the bottom of the part  206  of the block  203  (FIG. 41) and the latter is received in the longitudinally extending recess  207  in the bottom of the body part  205 , an exterior surface  232  of the block  203  is substantially coplanar with the exterior surface  233  of a block  160  (FIGS. 34 and 35) when the spline  230  (FIG. 43) is received in the longitudinally extending recess  169  in the bottom of that block; similarly; an interior surface  234  of the block  203  is substantially coplanar with the interior surface  233  of a block  160  (FIGS. 34 and 35) when the spline  229  (FIG. 43) is received in the longitudinally extending recess  169  in the bottom of that block Accordingly, after one of the blocks  203  is positioned as described above on the spines  229  and  230  (FIG.  43 ), two blocks  160  can be added to the structure, one with the spline  230  received in the recess  169  in its bottom and the tongue  211  of the previously positioned block  203  received in its groove  165 , and the other with the spline  229  received in the recess  169  in its bottom and its tongue  164  received in the groove  216  of the previously positioned block  203 . One of the blocks  204  (FIG. 42) can then be added to the structure with spies in the blocks therebelow received in the longitudinally extending recesses  220  and  225  in its bottom. Thereafter, additional splines, blocks  160 , stepped rods  179 , blocks  203  and  204  and cap  188  can be assembled, generally as previously described except that the blocks  203  and  204  are alternated at the end of the structure where the two walls intersect, and additional intersecting walls can be assembled in a similar manner. 
     A spline  235  is shown in FIG. 43 extending at a right angle to the spine  230 . Blocks  236  (FIG. 44) or blocks  236  and blocks  237  (FIG. 45) can be used with this spline and with blocks  160  to produce a wall which abuts, but is not connected to, a wall constructed as described above on the spine  230 . Referring to FIG. 44, the block  236  has a planar end  238 , and longitudinally extending recesses  239  and  240  in its top and in its bottom The recess  240  also extends in an end  241 , but the recess  239  terminates short of a groove  242  in the end  241 . The block  237  (FIG. 45) has a planar end  243 , a longitudinally extending recess  244  in its top, in an end  245  and in its bottom and a longitudinally extend recess  246  in its top and bottom. The recess  246  terminates short of a tone  247  in the end  245  of the block  237 . To produce a wall which abuts one constructed on the spline  230 , one of the blocks  236  is positioned with its planar end  238  adjacent the wall constructed on the spine  230 , and a part of the spline  235  received in the long all extending recess  239  in its bottom, an the wall can be produced as described above, using blocks  160  and additional blocks  236 , all of which are adjacent the wall constructed on the spline  230 . Alternate ones of the blocks  236  can have major surfaces which are one foot by one foot, with blocks  236  having major surfaces which are one foot by two feet between. The wall so constructed can terminate with blocks  236  whose ends  238  may be adjacent another wall, or exposed. Alternate ones of the blocks  236  used to terminate the wall can have major surfaces one foot by one foot, while those between can have major surfaces one foot by two feet. Blocks  237  with major surfaces either one foot by one foot or one foot by two feet can also be used, either in place of or in addition to blocks  236 . 
     The blocks  236  and  237  of FIGS. 44 and 45 can also be used to border openings in a wall, for example, openings to accommodate doors or windows. 
     Blocks  252  (FIG. 46) and  237 FIG. 45) can also be used with the spline arrangement of FIG. 43 to produce a structure which includes two adjacent walls which are locked to one another, wherein one of the walls extends at 90° to the other. To produce such a structure, a block  252  is placed above the spline  230 , with the spline  230  received in a longitudinally extending recess  253  in the bottom of the block  252 , and a block  237  is placed above the spline  235 , with the spline  235  received in the longitudinally extending recess  246  in the bottom of the block  237 . The blocks  252  and  237  are then positioned on the spines  230  and  235  so that the recess  246  in the top of the former is aligned with a lateral recess  254  in the top of the latter, and an arm  255  of a lock  256  is inserted in one of the recesses  172  (which is also identified by the reference numeral  262 ) in the top of the block, with a body part  258  of the lock in the aligned recesses  246  and  254  of the blocks  237  and  252  and a second arm  259  in the longitudinally extending recess  253  of the block  252 , so that the lock  256  prevents longitudinal movement of the block  237  relative to the block  252 . 
     Additional blocs can then be stalled on the spline  230  on both sides of the block  252 , and one of the blocks  203  and  204  (FIGS. 41 and 42) can be installed at the end of the spline  230 , and engaged as described above with the spline  229 . A second course, and higher courses, can then be installed, in the manner previously described, over the spline  200 . In the second course, the longitudinal extending recess  246  of the block  237  above the spline  235  will be aligned with the intersection between two blocks  160  (FIG. 34) or  252  (FIG.  46 ), so that the mechanism described above can not be used to prevent longitudinally movement of the abutting blocks. In the third, fifth and seventh courses, however, one of the blocks  252  (FIG. 46) can be locked to one of the blocks  237  (FIG. 45) above the spline  235 . 
     A block  260  (FIG. 48) having a major face one foot by one foot can be used instead of the block  204  of FIG. 42 to connect a course of blocks installed on the spline  230  with a course of blocks installed on the spline  229 . Similarly, a block  260  (FIG. 48) having a major face two feet by one foot can be so used instead of the block  203  of FIG.  41 . The block  260 , in either case, has a lateral recess  261  which, when the block  260  is on the spline  230  as the last block of a course, is so positioned relative to the spline  229  that the longitudinally extending recess  246  of a block  237  (FIG. 45) which is on the spline  229 , is align therewith, and, when the two blocks abut, the arm  255  of the lock  256  can be inserted in one of the recess  172  (also designated  262 ) in the top of the block  237 , with the body part  258  of the lock in the aligned recesses  246  and  261  of the blocks  237  and  260  and the second arm  259  in a longitudinally extending recess  263  of the block  260 , so that the lock  256  prevents longitudinal movement of the block  237  relative to the block  260 . 
     A block indicated generally at  263  in FIGS. 49 and 50 can also be used to construct the top course of a wall according to the invention. The block  263  is identical in most respects to the block  160  of FIGS. 34 and 35, differing in that it has a top surface  264  which slopes downwardly from a back  265  to a front  266 , has a longitudinally extending central recess  267 , has a narrow tongue  268  and vertically extending openings  269  and  270  above and below a groove  271  at the end of the block  263  which is opposite the tongue  268 . The opening  269  is between the central recess  267  and the top of the groove  271 , while the opening  270  is from the bottom of groove  271  through the bottom of the block. 
     Before a block  263  is installed as a part of a top course of blocks of a wall, the threaded end  272  of a bolt  273  (FIG. 50) is inserted through the openings  269  and  270  of the block, and a nut  274  is threaded onto the end  272 . The block  263  is then slid onto a spline on the course of blocks below the top (not bated in FIG. 50) and is moved to the desired position longitudinally of the spline. An angled tip  275  of the bolt  273 , which is threaded, is then slipped through an opening in the spline on which the block has been installed, and a nut  276  is threaded onto the tip  275 . After a block has been installed, as just described another block is fitted with a bolt, is slid onto the spline, and is moved so that its tongue  268  is received in the groove  271  of the previously installed block, where it is adjacent the bolt  273 . After the top course is complete (which may require blocks having the top configuration of the block  263 , but the overall shape of the block  162 , FIGS. 39 and 40, of the block  203 , FIG. 41, of the block  204 , FIG. 42, of the block  237 , FIG. 45, of the block  236 , FIG. 44, of the block  252 , FIG. 46, or of the block  260 , FIG.  48 ), a channel shaped portion  277  of a metal insert  278  is placed in the now aligned central recesses  267  of the blocks  263 . Free edges  279  and  280  of the in are closely adjacent the top surfaces of the blocks  263 , and extend a short distance beyond. A roof for the structure of which blocks  263  are a part can be bolted to the edges  279  and  280 . 
     The blocks  160 ,  162 ,  203 ,  204 ,  236 ,  252  and  260  can all be produced in appropriately shaped molds similar to the mold  133  of FIGS. 30-32, by casting a cement into the mold and, after the cement has cured introducing into the mold a composition, which will expand and cure to form a urethane body, and closing the mold. The mold (not illustrated) in which the block  160  is produced has a bottom portion which is shed to form a substantial planar major surface  248  and the top, bottom and two ends of a cement part  249  (FIG. 37) of the block  160  and the top, bottom and two ends of a urethane part  250 , and is closed by a cover which forms a substantially planar major surface  251  of the urethane part as the composition expands into contact with the cover and cures to form the urethane body. The molds in which the blocks  162 ,  203 ,  204 ,  236  and  237  are produced have shapes analogous to that just described, differing only as necessary to produce the different shapes. Care should be taken to prevent adhesion between the cement and the urethane compositions and the surfaces of the mold which they contact. Adhesion can be prevented by providing a polyethylene or equivalent surface on the mold surfaces, for example by using mold parts that have been produced from polyethylene by injection molding, or by using mold liners that have been produced from polyethylene by injection molding. 
     The cement that is used to produce the part  249  of the block  160  and the analogous parts of the other blocks, as described above, can be a mixture of 70 parts Type 1 hydraulic cement, 15 parts “2 mil” calcium carbonate, 15 parts “10 mil” calcium carbonate, V 2  part calcium oxide, and 100 parts water. 
     Another cement that can be used to produce the cement part  249  of the block  160  and the analogous parts of the other blocks can be a mixture of 70 parts Type 1 hydraulic cement, 10 parts “2 mil” calcium carbonate, 10 parts “10 mil” calcium carbonate, 100 parts ceramic microspheres, and sufficient water to provide a desired consistency for working. Ceramic microspheres which are commercially available from Minnesota Mining and Manufacturing under the designation G3500 have been used; these microspheres range in diameter from 105 to 155 μm, and have a surface area of 0.08 m 2 .cc −1 . Ceramic microspheres which are commercially available from Fillite USA, Inc., Huntington, W.V., under the designations “Fillite 52/7/5” and “Fillite 200/7” have also been used. 
     It is often desirable to accelerate the initial rate of hydration of the hydraulic cements in compositions identified in the two preceding paragraphs so that parts of structures according to the instant invention which are produced therefrom harden more rapidly, and, as a consequence, can be handled sooner after they are formed. Wheat flour can be added to the compositions to cause such acceleration. For example, from 1 to 20 parts of wheat flour, preferably from 5 to 15 parts and, most desirably, about 10 parts, can be added to either of the compositions identified in the indicated paragraphs. 
     The composition that expands to form the urethane part  250  of the block  160  can be produced from an intermediate composition and a liquified MDI. The intermediate composition can be produced from “Dyligomer I” whose production is described above, by thorough mixing of 100 parts of the Dyligomer I solution, 28.1 parts of triallyl cyanurate, 1 part of benzoyl peroxide, 1.5 parts of cobalt naphthenate, 1 part of dimethyl aniline, 1.2 parts of a silicone surfactant that is commercially available from Dow Corning under the designation DC 193, 90 parts of 5 micron calcium carbonate (325 mesh), 0.5 part of water and 1 part of a polymeric colorant. 
     The composition that is introduced into the mold to produce the urethane part  250  of the block  160  can be a mixture of the intermediate composition and a liquified MDI. The mixture of the liquefied 4,4′-MDI and the intermediate composition of Example 1 can be produced in the apparatus of FIG.  33 . The MDI is charged to the vessel  152  (FIG.  33 ), and the intermediate composition is charged to the vessel  153 . The MDI is then pumped from the vessel  152  through the line  154  to the meter  155 , while the composition in the vessel  153  is pumped from the vessel  153  through a line  156  to the meter  155 , which is set to deliver the MDI at a rate of 44.6 parts per minute and the intermediate composition in the vessel  153  at a rate of 100 parts per minute through the line  157  to the mixer  158  where they are rapidly and thoroughly mixed before being discharged through the line  159  into the shell  132 . The MDI introduced into the line  159  can contain substantially 1.05 NCO groups per OH group in the intermediate composition introduced into the line  159 . A charge of 4 pounds of the mixture into the mold produces a one foot by two feet block  161  having a urethane part  188  which has an apparent density of 12 pounds per cubic foot. 
     Panels similar to that designated  124  in FIG. 29, except that the parallel major surfaces were composed of 19 gauge sheet metal have also been produced by supporting appropriately sized panels of the sheet metal against plywood backing, closing the spaces between the edges and the ends of the metal panels with plywood sheets faced with polyethylene, and introducing the composition which formed the cured urethane core into the space between the metal sheets. Such panels about one inch in thickness have been found to be highly useful in building construction. 
     In another embodiment of the invention of FIG. 23, the bodies  106  of polymeric material in the side members can extend above the upper stop  103  and below the sill  104  a sufficient distance, and can be so sized that they constitute studs of a wall structure in which the window frames are installed. 
     It will be appreciated that various changes and modifications can be made from the embodiments of the instant invention that have been described above without departing from the spirit and scope thereof as defined in the attached claims. For instance, Example 1 can be repeated except that the mold  14  is charged with about 1040 g of the composition flowing from the line  28  per 929 cm 2  of aluminum floor surface, disregarding the area of the legs which extend vertically in FIG.  2  and the area of the horizontally extending surfaces which face downwardly in FIG. 2. A sheet of a polyethylene sheet can then be placed over the polyol/diisocyanate composition, and the lid  17  of the mold can be closed. The urethane then foams until it is compressed between the lid  17  and the aluminum floor. The final product being a load-bearing floor, roof or the like structure having opposed, substantially parallel major surfaces and a body of a thermoset foam disposed between the major surfaces, one of the opposed major surfaces being a surface of a metal sheet, and there being legs which are structurally integral with the metal sheet and extend into the thermoset foam toward the opposed major surface, and the other of the major surfaces being a surface of the body of thermoset foam, the structure having been produced by confining the metal sheet, the legs and a quantity of a foamable, thermosetable composition which foams and cures to a thermoset condition in a mold, the quantity of the composition being sufficiently great that foaming thereof forces the composition into intimate contact with the legs and the metal sheet and the body of the thermoset foam has an apparent density of at least 8 pounds per cubic foot, and is tightly bonded to the legs and to the metal sheet. 
     Example 1 can also be repeated except that the expanded polystyrene sheet  13  is replaced by a plywood sheet having the same dimensions which has been wrapped in polyethylene, and has a number of small diameter holes through both the plywood and the polyethylene sheet to vent air that would otherwise be entrapped in the mold as the foamable urethane expanded. After the urethane foams and cures enough to be self supporting, the foamable composition of either of Examples 2 and 3 can be placed on top of the urethane foam in the mold  14 , the lid  17 , suitably separated from the interior of the mold  14 , e.g., by a polyethylene sheet, can be closed, and heat can be supplied to the phenolic composition in the mold to cause it to foam and cure to a thermoset condition. The aluminum floor  11  can be heated dielectrically, or the entire assembly can be placed in a low temperature oven to cause the phenolic to foam and cure. 
     While the use of polymerizable compositions containing a dyligomer to produce various structures has been described herein, it will be appreciated that many of the advantageous of the structures could be realized if a conventional composition which did not include a dyligomer were used instead. By way of example, a conventional composition which could be used can be formulated from 100 parts of a sucrose polyol, hydroxyl number 400, that is commercially available from BASF under the designation Pluracol 975 (functionality 2.3), 109 parts of methylene diphenyldiisocyanate (“MDI”), 1.5 parts of a silicone surfactant that is commercially available from Dow Corning under the designation DC 193, 90 parts of 5 micron calcium carbonate (325 mesh), 0.63 part of water and 1.25 parts of dibutyl tin dilaurate. The MDI can be charged to the vessel  22  (FIG.  1 ), while the other constituents of the batch are mixed thoroughly, and charged to a vessel  23 . MDI can then be pumped from the vessel  22  through the line  24  to the meter  25 , while the composition in the vessel  23  is pumped from the vessel  23  through the line  26  to the meter  25 , which can be set to deliver the MDI at a rate of 10.09 parts per minute and the composition in the vessel  23  at a rate of 19.39 parts per minute through the line  27  to the mixer  28  where they were rapidly and thoroughly mixed before being discharged through the line  29  into the mold  14 , which can be any of the molds previously disclosed herein. 
     Further, various wall panels in addition to that indicated at  124  in FIG. 29 can be produced. For example, a sheet of wood, plasterboard, tile, marble or a sheet which has another desired surface, and, in any case, is sized to cover the surface  135  of the mold  133  (FIG. 30) can merely be placed on the surface  135 , a charge of a suitable composition, for example, that used as described above to produce the core  125  of the panel  124 , can be placed on the sheet of wood, plasterboard, or the like, a second sheet can be placed above the composition, and a flat platen can be positioned above the second sheet so that the expansion of the composition, as it foams, forces the second sheet upwardly into contact with the platen, and forms a panel of the cured, cellular urethane having a desired thickness. The two sheets that are used in producing a wall panel can also be separator sheets, e.g., of polyethylene, so that the panel consists of the thermoset, cellular urethane. Any excess urethane at the edges of a panel can merely be removed, or the suitably supported sheets of a separator material can be have side walls to contain the foaming composition within the space between the two sheets. 
     Other changes and modifications will be apparent to one skilled in the art, and can be made without departing from the spirit and scope of the invention as defined in the appended claims.