ISOCYANATE-MODIFIED POLY(ALKYLENE CARBONATE) POLYAHLS, PREPOLYMERS AND URETHANE/UREA POLYMERS PREPARED THEREFROM

Abstract: This invention relates to isocyanate-modified poly(alkylene carbonate) polyahls comprising the residue of at least one polyahl, at least one isocyanate modifier, poly(alkyleneoxy) units, poly(alkylene carbonate) units, and a plurality of active hydrogen end groups. This invention also relates to isocyanate-functional prepolymer compositions of these isocyanate-modified poly(alkylene carbonate) polyahls, which contain the residue of at least one isocyanate-modified poly(alkylene carbonate) polyahl of this invention and excess organic polyisocyanate units. This invention further relates to urethane/urea polymers formed by the reactions of the isocyanate-functional prepolymers with polyahls; and the urethane/urea polymers comprising the residue of at least one isocyanate-modified poly(alkylene carbonate) polyahl of this invention, the residue of a polyisocyanate and the residue of at least one other polyahl selected from the group consisting of polyamines and polyfunctional hydroxyl compounds. The novel compositions of this invention are useful in urethane/urea polymer applications such as, for example, foam elastomers, plastics, adhesives and coatings.

Description: ISOCYANATE-MODIFIED POLY(ALKYLENE CARBONATE) POLYAHLS, PREPOLYMERS AND URETHANE/UREA POLYMERS PREPARED THEREFROM This invention relates to polymeric composi¬ tions containing a poly(alkylene carbonate) backbone. Polyether polyols and polyester polyols are well-known polymers which can be further polymerized with organic polyisocyanates to prepare polyurethanes. Polyether polyols are prepared by the reaction of hydroxy-containing hydrocarbons, such as an aromatic or aliphatic diol or triol, and epoxides, e.g., ethylene oxide and propylene oxide. Polyester polyols are pre- pared by the reaction of polyacids, such as adipic or terephthalic acid, or esters of polyacids, such as dimethyl adipate or dimethyl terephthalate with dihy- droxy-containing hydrocarbons, such as aromatic and aliphatic diols and triols. Some poly(alkylene carbon¬ ate) polyol properties resemble polyester polyol prop¬ erties while other properties resemble polyether poly- ols. It is known to prepare polycarbonates from ali¬ phatic dihydroxyl compounds either by a process of phosgenation in which hydrogen chloride is liberated or bound by bases, such as pyridine or quinoline, or by a SUBSTITUTE SHEET process of transesterification with carbonic acid esters of alcohols or " phenols, preferably diphenylcar- bonate, optionally with the aid of transesterification catalysts. In either case, it is essential to use phosgene or a mixture of carbon monoxide and chlorine as the source of carbonic acid. Technical processes which involve the preparation and handling of phosgene are difficult and costly on account of considerable safety risks involved and the high cost of materials 10 due to corrosion. To -this are added ecological prob¬ lems since either the spent air is contaminated with hydrogen chloride or the effluent water is contaminated with sodium chloride. T5 Polycarbonates produced by these methods, using dihydrocarbyl compounds, may have a functionality of less than two due to inadequate or incomplete esterifi- cation or transesterification which often prevents the 2 Q products from forming high molecular weight polymers in subsequent reactions. U.S. patents 3,248,414; 3,248,415 and 3,248,416 to Stevens disclosed the preparation of poly(alkylene 2c carbonate) polyols from (1) carbon dioxide and 1 ,2-epoxides; (2) cyclic carbonates such as ethylene carbonate; or 30 (3) cyclic carbonates and a 1,2-epoxide. A minor amount of a polyol is employed therein as an Initiator. The reaction is usually conducted in the SUBSTITUTE SHEET -3- presence of a metal carbonate, metal hydroxide, tri- sodiu phosphate or tertiary amine. PolyCalkylene carbonate) polyols have also been c prepared by polymerization of ethylene carbonates under pressure using basic catalysts and a minor amount of glycol as initiator as disclosed in U.S. patent 4,105,641 to Buysch et al. These products are low in carbonate and high in ether group concentration due to 10 decomposition of the ethylene carbonate. In the Stevens patents discussed hereinbefore, a polyCalkylene carbonate) polyol derived from ethylene carbonate and monoethylene glycol was exposed to temperatures of 160°C at 2 mm Hg C265 Pa) of pressure to remove unreacted J ethylene carbonate. In U.S. patent 3,379,693, Hostetler removed unreacted ethylene carbonate from products similar to polyCalkylene carbonate) polyols by heating to 130°C under a pressure of 1-5 mm Hg (133-665 0 Pa). In U.S. patent 3,896,090 to Maximovich, ethylene carbonate was reacted with diethylene glycol and the reaction product treated under reduced pressure to remove the unreacted ethylene carbonate and diethylene glycol. 5 Several workers have prepared polyCalkylene carbonate) polyols and related materials by controlling the equilibrium between the reaction materials of a diol and alkylene carbonate and the products of a poly- 0 (alkylene carbonate) polyol and monoethylene glycol. The reaction is controlled by the removal of monoethyl¬ ene glycol. In U.S. patent 3,133,113 to Malke us, ethylene carbonate and diethylene glycol were reacted at 125°C to 130°C under a reduced pressure of 100 mm Hg (13,300 Pa) SUBSTITUTE SHEET -4- in the presence of certain catalysts with concurrent removal of monoethylene glycol as a distillate. The catalyst employed was a mixed zinc borate-alkaline earth metal oxide catalyst. This was followed by removal of starting material. The Malkemus procedure is plagued by the presence of volatile ethylene carbonate which condenses as a solid throughout the system causing severe plugging and reducing ethylene carbonate conversion while monoethylene glycol is being removed. This process requires large excesses of ethylene carbonate. In U.S. patent 3,313,782 to Springmann et al. , this process was further studied under reduced pressure in the presence of catalysts, and limits on the reac¬ tion conditions were set. . The reaction temperatures must be lower in this process than the boiling point of the alkylene carbonate, but still high enough to dis¬ 0 till off the monoethylene glycol formed. U.S. patent 4,131,731 to Lai et al. used stage reductions in pressure during the reaction of alkylene . carbonate with a diol. The final stage of the Lai c et al. process is intended to remove monoethylene gly¬ col. The patentees characterized their reaction condi¬ tions by stating'that the alkylene carbonate must have a boiling point 4.9°C greater than monoethylene glycol. The chemistry based on the above equilibrium was im- 0 proved upon by U.S. patent 4,105,641 to Buysch et al. where the reactions were carried out in a solvent (e.g., cumene) capable of removing monoethylene glycol as an azeotrope with the solvent. Heretofore, the molecular weights of poly(al¬ kylene carbonate) polyols from alkylene carbonates have SUBSTITUTE SHEET been controlled by either the stoichiometry of the reactants, that is, higher alkylene carbonate to ini¬ tiator ratios for higher molecular weights, or the removal of monoethylene glycol from the reaction mix¬ ture with an ethylene carbonate to initiator equivalent ratio of 1. Catalysts are used in most cases since reaction-rates are very slow in the absence of a catalyst. When high alkylene carbonate to initiator ratios are used to make higher molecular weight poly- 10 (alkylene carbonate) polyols, reaction rates drop severely as higher conversions are approached. In these cases, long reaction times are required and the products are contaminated by unreacted alkylene carbon¬ 15 ate. If temperatures are increased to increase the rate, product decomposition occurs' with CO2 loss. In view of the deficiencies of the conventional poly(alkylene carbonate) polyahls, it would be highly 20 desirable to provide poly(alkylene carbonate) polyahls having improved physical and chemical properties. In one aspect, this invention is a new, isocya¬ nate-modified poly(alkylene carbonate) polyahl which is - f - a polymer comprising (1) a backbone having (a) the res¬ idue of at least one polyahl initiator, (b) the residue of at least one polyisocyanate, (c) a plurality of poly(alkyleneoxy) moieties, (d) a plurality of poly- (alkylene carbonate) moieties; and (2) a plurality of 30 active hydrogen end groups. In a second aspect, this invention is an iso¬ cyanate-functional prepolymer composition of the iso¬ cyanate-modified polyCalkylene carbonate) polyahl formed by reaction of the isocyanate-modified polyCal- SUBSTITUTESHEET kylene carbonate) polyahl with an excess of one or more polyisocyanates. In a third aspect, this invention is a novel urethane/urea polymer formed by the reactions of the isocyanate-functional prepolymer composition with any polyahl. In a -fourth aspect, this invention is a novel urethane/urea polymer formed by the reactions of the novel, isocyanate-modified polyCalkylene carbonate) polyahl of this invention with polyisocyanates, option¬ ally in the presence of other polyahls. The introduction of the residue of an isocya¬ nate into the backbone of the polyCalkylene carbonate) polyahl allows adjustment of the physical and chemical properties of the polyCalkylene carbonate) polyahl to maximize its effectiveness in specific applications. For example, the isocyanate-modified polyahls of this invention are useful for producing materials for appli¬ cations in flexible urethane foams, urethane coatings, rigid urethane foams, urethane/urea elastomers and plastics, adhesives, polymeric coatings and surfactants among others. In some systems property improvements include increased modulus, increased strength, improved elongation to break, improved solvent resistance and increased hardness when compared to the corresponding systems without the isocyanate modification. The starting materials for the novel compo¬ sitions of this invention are polyCalkylene carbonate) polyahls and polyisocyanates. PolyCalkylene carbonate) polyahls are ran¬ domized polymers having a plurality of carbonate moi- SUBSTITUTE SHEET r -7- eties and a plurality of active hydrogen moieties and optionally other moieties such as- di- and higher poly- alkyleneoxy units. An alkylene carbonate moiety is a repeating unit which has an alkylene group bound to a carbonate moiety. An active hydrogen moiety is a moi¬ ety containing a hydrogen atom which because of its position in the moiety displays significant activity according to the Zerewitinoff test described by Kohler in the Journal of American Chemical Society , Vol. 49, p. 3181 (1927). Illustrative of such active hydrogen moieties are -COOH, -OH, -NH 2 , -NH-, -C0NH 2 , -SH and -C0NH-. Alkyleneoxy moiety refers herein to a repeating unit which has an alkylene group bound to oxygen. Alkylene carbonate and alkyleneoxy moieties are respectively represented by the following formulae: fC(R 2 ) 2 -C(R 2 ) 2 -0C0t It 0 and fC(R 2 ) 2 -C(R 2 ) 2 -0 wherein R 2 is as hereinafter defined. Preferred polyCalkylene carbonate) polyahls are random polyols represented by the formula: Rl{XfC(R2) 2 C(R2) 2 0 y fC(R2) 2 C(R2) 2 0CQ^ x (Rl(XA) n > 1 ) z -H} n I wherein SUBSTITUTE SHEET R 1 is separately in each occurrence an n-valent hydrocarbon radical or hydrocarbon radical which can contain one or more heteroatoms of 0, N or S; R 2 s separately in each occurrence hydrogen, halogen, a nitro group, a cyano group, a C- |-2Q hydrocarbyl group or a ' C 1-2 Q hydrocarbyl group sub¬ stituted with one or more of the following: a • halo, cyano, nitro, thioalkyl, tert-amino, alkoxy, aryloxy, aralkoxy, carbonyldioxyalkyl, carbonyldi- oxyaryl, carbonyldioxyaralkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, arylcarbonyl, aralkylcarbonyl, alkylsulfinyl, arylsulfinyl, aralkylsulfinyl, alkylsulfonyl, arylsulfonyl, or aralkylsulfonyl group; X is separately in each occurrence S, 0, NH, 0 0 0 It It If -CO- , -0C0- , or -0CNH- ? A is separately in each occurrence 0 It C R 2 ) 2 C(R 2 ) 2 -0CQ-)- χ , fC(R 2 ) 2 CCR 2 ) 2 0^- y » combinations thereof or a covalent bond; Q is separately in each occurrence 0, S or NH provided that all carbonate moieties are internal because terminal carbonate moieties are unstable and form OH moieties by the elimination of C0 2 ; n is separately in each occurrence an integer of from 1 to 25; x is separately in each occurrence an integer of from 1 to 40; y is separately in each occurrence an integer of from. 1 to 120; and z is separately in each occurrence an integer of from 0 to 5. A more preferred class of polyCalkylene car¬ bonate) polyahls are polyCalkylene carbonate) polyols generally corresponding to the aforementioned formula wherein R^, R 2 and n are as previously defined; X is oxygen; x is separately in each occurrence an integer from 2 to 10; y is separately in each occurrence an integer from 5 to 15; and z is an integer from 0 to 2; provided that the ratio of y to x is from 1:1 to 3:1. In the hereinbefore-defined formulae, R^ is preferably an aliphatic or cycloaliphatic hydrocarbon containing one or more oxygen, nitrogen or sulfur moi¬ eties; R 1 is more preferably an n-valent alkane or cycloalkene, or an n-valent alkane or cycloalkane con¬ taining one or more oxygen, nitrogen or sulfur moi- eties; R' is even more preferably an n-valent C- | _I Q alkane or an n-valent C - |Q alkane substituted with one or more oxygen moieties. • R 2 is preferably hydrogen, ^1-20 a l k yl» C 1-20 haloalkyl, C-|_ 2Q alkenyl or phenyl; R 2 is more preferably hydrogen, ' Cη — 3 alkyl, C 2 _3 alkenyl, or phenyl; R 2 is even more preferably hydro¬ gen, methyl or ethyl; R 2 is even more preferably hydro¬ gen or methyl, and, most preferably, hydrogen. X is preferably S, 0 or NH; X is most preferably 0. Prefer¬ ably, n is an integer of 1 to 10, inclusive; more pref- SUBSTITUTE SHEET erably, 1 to 5, inclusive; and, most preferably, 1 or 2. As used herein, the term "polyahl" includes any c polyfunctional compound having on average more than 1 active hydrogen moiety as defined hereinbefore. Speci¬ fically included within the definition of polyahl are polyols, polyamlnes, polya ides, polymercaptans and polyacids. Examples of polyahls suitable for use in 10 the instant invention may be found in U.S. Patent 4,465,713 at column 2, line 42 through column 5, line 17. PolyCalkylene carbonate) polyahl starting mate- 15 rials useful in this invention are prepared by any method known in the art, such as the condensation of an alkylene carbonate, carbon dioxide and an alkylene oxide, or mixtures of an alkylene carbonate, an alkyl¬ ene oxide and/or C0 2 , with an organic compound contain¬ 20 ing one or more active hydrogen atoms Cinitiator) in the presence of an alkaline catalyst or metal salt of an alkaline compound. Examples of these polyCalkylene carbonate) polyols and methods for preparation of these 2c polyols are contained in Maximovich (U.S. Patents 3,896,090 and 3,689,462), Springmann (U.S. Patent 3,313,782), Stevens (U.S. Patents 3,248,416; 3,248,415; and 3,248,414), and U. S. application Serial No. 750,362. Alternatively, the poly(alkylene carbonate) 30 polyols can be prepared by reacting a dialkyl carbonate or diaryl with an initiator with two or more hydroxyl moieties. See, for example, U.S. patents 4,476,293 and 4,191,705. The polyCalkylene carbonate) polyahls used as starting materials may also contain the residue of an SUBSTITUTE SHEET initiator as well as unreacted starting materials and other relatively volatile reaction products. The organic compound containing active hydrogen atoms (the initiator) is a hydrocarbon or hydrocarbon which is substituted with one or more heteroato s of oxygen, nitrogen or sulfur containing between 1 and 25 functional groups containing between 1 and 25 function¬ al groups containing a reactive hydrogen. Among the desirable initiators are those which correspond to the formula R 3 fXH) n wherein R 3 , X and n are as hereinbefore defined. A functional group containing a reactive hydrogen means herein any moiety which contains a hydrogen atom which will readily react with an alkylene carbonate, a dial¬ kyl carbonate, diaryl carbonate or an alkene oxide in the presence of carbon dioxide. More specifically, reactive hydrogen means herein a hydrogen linked directly to an oxygen, nitrogen or sulfur atom, such as is found in a hydroxy, non-tertiary amine," amide, mer- capto or carboxyl group. The organic compounds containing active hydrogen atoms of this invention (the initiator) contain one or more of the following functional groups, hydroxyls, amines, mercaptans, carboxyls, sulfones, amides, imides, or carbonates. In addition, the initiators may contain other groups in their backbone structure, such as, for example sulfones, sul oxides, sul ides, amines, amides, ethers, esters and carbonates. SUBSTITUTE SHEET Among desirable initiators are polyols such as aliphatic polyether and polyester polyols, cycloali- phatic polyols, aromatic polyols and polyols which further contain oxy or ether groups; polyamines; poly- mercaptans; polyamides; polycarboxylic acids; water, alkylolamines and organic compounds which contain two or more of the above-described functional groups con¬ taining reactive hydrogens. The preferred classes are the polyols, polyamines and polymercaptans. Examples of active hydrogen-containing compounds include those described in the U.S. patents mentioned hereinbefore. Two or more initiators can be used in combination to obtain a poly(alkylene carbonate) polyol. Catalysts used in the preparation of polyether polyols include alkali metal hydroxides, alkaline earth " metal hydroxides, alkali metal carbonates, alkaline earth metal carbonates, ammonium hydroxide and ammonium 0 carbonate. Preferable catalysts for the reaction of an active hydrogen-containing organic compound with an alkylene carbonate, dialkyl carbonate, diaryl carbon- c ate, alkylene oxide and carbon monoxide, or alkylene carbonate in admixture with an alkylene oxide and/or carbon dioxide include ester exchange catalysts. Among preferable catalysts are such metals as lithium, sodi¬ um, potassium, rubidium, cesium, magnesium, calcium, 0 strontium, barium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic and cerium as well as the alkoxides thereof. Examples of other pref¬ erable catalysts are alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonates, alkali metal borates, alkaline earth metal borates, ammonium borates, hydrocarbyloxy titanates, zinc borate, lead SUBSTITUTE SHEET -13- borate, zinc oxide, lead silicate, lead arsenate, litharge, lead carbonate, antimony trioxide, germanium dioxide, cerium trioxide and aluminum isopropoxide. Examples of other preferable catalysts include salts of organic acids of magnesium, calcium, cerium, barium, zinc and titanium, alkali metal stannates, alkaline metal stannates and ammonium stannates. Examples of borate catalysts include sodium meta-borate, sodium meta-borate tetrahydrate, sodium meta-borate dihydrate, sodium pentaborate pentahydrate, sodium tetraborate decahydrate, sodium tetraborate pen¬ tahydrate, diammonium tetraborate tetrahydrate, ammo¬ nium hydrogen tetraborate tetrahydrate, lithium ortho- -dihydroborate, lithium meta-borate, lithium tetrabor¬ ate, lithium pentaborate pentahydrate, potassium meta- -borate, potassium tetraborate tetrahydrate, potassium tetraborate pentahydrate, potassium pentaborate tetra- hydrate, magnesium meta-borate trihydrate, magnesium diborate, magnesium ortho-borate, calcium meta-borate, calcium tetraborate and strontium tetraborate tetrahy¬ drate. Examples of stannate catalysts include sodium stannate trihydrate, potassium stannate trihydrate, potassium stannate monohydrate, barium stannate trihy¬ drate and magnesium stannate trihydrate. More preferred catalysts are the alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonates, alkali metal stannates, alkaline earth metal stannates, alkali metal borates, alkaline earth metal borates and ammonium borates. Even more pre¬ ferred catalysts are alkali metal carbonates, alkali metal borates and alkali metal stannates. Most pre- SUBSTITUTE SHEET ferred catalysts are potassium carbonate, sodium meta- -borate and sodium stannate. The choice of catalyst affects the percentage of carbon dioxide units in the poly(alkylene carbonate) polyol. Generally, the poly(alkylene carbonate) polyol contains between 5 and 35 weight percent of the carbon dioxide. The use of most of the catalysts described hereinbefore results in a poly(alkylene carbonate) 10 polyol in which 10 percent of the units are carbon dioxide units, whereas the use of sodium meta-borate results in 25 percent carbon dioxide units, and the use of sodium stannate results in 30 to 50 percent carbon dioxide units. In this context, percent means the T5 percentage of the carbon dioxide units based on the total of the carbon dioxide units and the alkyleneoxy units. A suitable amount of the catalyst is any amount 20 which is catalytic under the reaction conditions. Preferable catalyst concentrations are between 0.01 and 5 percent by weight based upon the weight of the reactants, more preferably between 0.01 to 1,0 percent 2r - by weight, and most preferably 0.05 to 0.1 percent by weight. It is preferred to remove the catalysts used to prepare the starting poly(alkylene carbonate) polyahls 30 prior to advancing these polyahls to higher molecular weights, as such catalysts can result in the decompo¬ sition of the poly(alkylene carbonate) polyahls at the temperatures used under molecular weight advancement conditions. While trace amounts of such catalysts can be present without significant decomposition, the bulk of the catalyst used to prepare the starting poly(al- SUBSTITUTE SHEET kylene carbonate) polyahls is removed prior to the advancement process of this invention. The combination of short reaction times in the presence of very low catalyst levels allows high molecular weight build with minimal decomposition. Catalyst can be removed conve¬ niently by the method of U.S. patent 4,528,364. The polyisocyanates suitable for making the novel compositions of this invention include aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates. Specific examples include ethylene diisocyanate, 1 ,4-tetramethylene diisocyanate, 1,6- -hexamethylene diisocyanate, 1 , 12-dodecane diisocya¬ nate, cyclobutane-1 ,3-diisocyanate, cyclohexane-1 ,3- and 1 ,4-diisocyanate and mixtures of these isomers; 1-isocyanato-3,3,5-trimethyl-5-isocyanato methyl cyclohexane (see e.g., German Auslegeschrift No. 1,202,785); 2,4- and 2,6-hexahydrotolylene diisocyanate and mixtures of these isomers; hexahydro-1 ,3- and/or 1 ,4-phenylene diisocyanate, perhydro-2,5'- and/or 4,4'- -diphenyl methane diisocyanate, 1,3- and 1 ,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate and mixtures of these isomers; diphenyl methane-2,4'- and/or 4,4'-diisocyanate, naphthylene-1 ,5-diisocyanate, triphenyl methane-4,4' ,4"-triisocyanate, polyphenyl polymethylene polyisocyanates of the type obtained by condensing aniline with formaldehyde, followed by phos¬ genation and such as described for example in British Patents 874,430 and 848,671; perchlorinated aryl poly¬ isocyanates of the type described in German Auslege- schrift 1,157,601; polyisocyanates containing carbodi- imide groups of the type described in German patent 1,092,007; diisocyanates of the type described in U.S. patent 3,492,330; polyisocyanates containing allopha- SUBSTITUTE SHEET nate groups of the type described, for example, ia British patent 994,890, in Belgian patent 761,626 and in published Dutch patent application No. 7,102,524; polyisocyanates containing isocyanurate groups of the type described in German patents 1,022,789; 1,222,067 and 1,027,394 and in German Offenlegungsschrift 1,929,034 and 2,004,048; polyisocyanates containing urethane groups of the type described, for example, in Belgian patent 752,261 or in U.S. patent 3,394,164; polyisocyanates containing acrylated urea groups as described in German patent 1,230,778; polyisocyanates containing biuret groups of the type described, for example, in German patent 1,101,392, in British patent 889,050 and in French patent 7,017,514; polyisocyanates obtained by telomerization reactions of the type described, for example, in Belgian patent 723,6-40; polyisocyanates containing ester groups of the type described, for example, in British patents 965,474 and 1,072,956, in U.S. patent 3,567,763 and in German pat¬ ent 1,231,688 and reaction products of the aforemen¬ tioned isocyanates with acetals as described in German patent 1,072,385. It is also possible to use the distillation residues containing isocyanate groups accumulating in the commercial production of Isocyanates, optionally in solution in one or more of the aforementioned polyiso¬ cyanates. In addition, it is possible to use mixtures of the aforementioned polyisocyanates. Additional polyisocyanates suitable for use in this invention include those described by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pp. 75-136, and in SUBSTITUTE SHEET U.S. patents 3,284,479; 4,089,835; 4,093,569; 4,221,876; 4,310,448; 4,359,550 and 4,495,309. One class of particularly useful polyisocya- c nates are the aromatic polyisocyanates such as 2,4- and 2,6-tolylene diisocyanates and mixtures of these iso¬ mers ("TDI"); polyphenyl-polymethylene polyisocyanates of the type obtained by condensing aniline with formal¬ dehyde, followed by phosgenation ("crude MDI") and, 10 polyisocyanates containing carbodiimide groups, ure¬ thane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups ("modified polyisocya¬ nates") . 15 A preferred class of aromatic polyisocyanates is methylene bis(4-phenylisocyanate) or MDI. Pure MDI, q ' uasi- and prepolymers of MDI, and modified pure MDI, may be used to prepare suitable RIM elastomers. Since pure MDI is a solid and, thus, often inconvenient to 0 use, liquid products based on MDI are often used and are included in the scope of the terms MDI or methylene bis(4-phenylisocyanate) used herein. U.S. patent 3,394,164 is an example of a liquid MDI product. More r- generally uretonimine modified pure MDI is included also. This product is made by heating pure distilled MDI in the presence of a catalyst. A preferred class of isocyanate-modified 0 poly(alkylene carbonate) polyahl compositions of this invention are random polymers which correspond to the formula SUBSTITUTE SHEET -18- RHXCCR^^CR^^^CR^^CCR^^CQ^lM -y HXA) ^ ,)^},, II wherein a 1 . X, A, Q, n, x, y and z are as pre- viously defined; M is separately in each occurrence the residue of an aliphatic, cycloaliphatic, araliphatic, aro¬ matic or heterocyclic polyisocyanate or a combina¬ tion thereof; X* is separately in each occurrence 0, S or NH; and s is separately in each occurrence an integer of from 1 to 5. A more preferred class are random isoeyanate- - odified polyCalkylene carbonate) polyols generally corresponding to formula II wherein R 1 , R 2 and n are as previously defined wherein X* is oxygen; x is separately in each occurrence an integer from 2 to 10; y is separately in each occurrence an integer from 5 to 15; and z is an integer from 0 to 2, provided that the ratio of y to x is from 1:1 to 3:1. SUBSTITUTE SHEET Preferred among the above are isocyanate-modi¬ fied polyCalkylene carbonate) polyols of the invention wherein R 1 is hydrogen, C- | _ Q alkyl, C- | _ 20 haloalkyl, C- | _ 2Q alkenyl or phenyl; X is S, 0 or NH; M is the residue of a polyisocyanate selected from the group consisting of toluene diisocyanate, methylene bis(4-phenylisocyanate) , quasi- and prepolymers of methylene bis(4-phenylisocyanate) and combinations thereof; and n is an integer from 1 to 10. Further preferred random isocyanate-modified polyCalkylene carbonate) polyols of the invention are those wherein R' is an n-valent alkane or cycloalkane, or an n-valent alkane or cycloalkane containing one or more oxygen, nitrogen, or sulfur moieties; R 2 is hydrogen, methyl or ethyl; X is 0; n is an integer from 1 to 5; and s is an integer from 1 to 3. Still more preferred are the isocyanate-modi¬ fied polyCalkylene carbonate) polyols wherein SUBSTITUTE SHEET -20- R 1 is n-valent C- | _ 2 o alkane or an n-valent Cι_ιo alkane substituted with one or more oxygen moieties; R 2 is hydrogen or methyl; and n is 1 or 2. The most preferred of the isocyanate-modified polyCalkylene carbonate) polyols is wherein R 2 is 10 hydrogen. Another preferred group of isocyanate-modified polyCalkylene carbonate) polyols of the invention are those random polymers which correspond to the formula t5 0 II {(R3 χ (C0) y fCCR 2 ) 2 CCR 2 ) 2 0) z {MX'} s -H} p III wherein 20 R 2 is as previously defined; R3 is R 4 -X 1 n ; is separately in each occurrence an n-valent 25 hydrogen radical or hydrocarbon radical which con¬ tains one or more heteroatoms of 0, N or S; X 1 is separately in each occurrence 0, S or NH; 30 M is separately in each occurrence the residue of an aliphatic, cycloaliphatic, araliphatic, aro¬ matic or heterocyclic polyisocyanate or a combina¬ tion thereof; SUBSTITUTE SHEET n is separately in each occurrence an integer of from 1 to 25; p is an integer of 1 or greater; s is an integer of from 1 to 5; x is 1 ; y is separately in each occurrence 1 to 40; and z is separately in each occurrence 1 to 100. A still more preferred group of random isocya¬ nate-modified polyCalkylene carbonate) polyols is that corresponding to formula III and wherein R 2 is hydrogen, C- | _ 2 Q alkyl, C- | _ 2 Q haloalkyl, C-|_20 alkenyl or phenyl; R 4 is an aliphatic or cycloaliphatic hydro¬ carbon or an aliphatic or cycloaliphatic hydro¬ carbon containing one or more oxygen, sulfur or nitrogen moieties; M is separately in each occurrence the residue of a polyisocyanate selected from the group con¬ sisting of toluene diisocyanate, methylene bis(4- -phenylisocyanate) , quasi- and prepolymers of meth¬ ylene bis(4-phenylisocyanate) and combinations thereof; X* is separately in each occurrence S, 0 or NH; n is an integer of 1 to 10, inclusive; p is 1 to 10, inclusive; SUBSTITUTE SHEET -22- y is 5 to 20, inclusive; and z is 20 to 50, inclusive. An even more preferred group of random isocya¬ nate-modified polyCalkylene carbonate) polyols corre¬ sponding to formula III is that wherein R 2 is hydrogen, C-J.J alkyl, C 2 _3 " alkenyl or phenyl; R 4 is an n-valent alkane or cycloalkane or an n-alkane alkane or cycloalkane containing one or more oxygen, sulfur or nitrogen moieties; n is an integer of 1 to 5, inclusive; p is an integer of 1 to 5, inclusive; s Is an integer of from 1 to 3, inclusive; and X' is 0. A yet more preferred group of random isocya¬ nate-modified polyCalkylene carbonate) polyols is that corresponding to formula III and wherein R 2 is hydrogen, methyl or ethyl; R 4 is an n-valent G-J_- |Q alkane; and n is 1 or 2. The novel, isocyanate-modified polyCalkylene carbonate) polyahl compositions of this invention con¬ tain several key components in their backbones. The residue of at least one polyahl initiator is present, typically, as the result of the particular initiator SUBSTITUTE SHEET employed to make the starting material, the polyCalkyl¬ ene carbonate) polyahl. The amount of initiator resi¬ due present is that amount necessary to make the desired molecular weight starting material. The products also include a plurality of poly¬ Calkylene carbonate) moieties. These moieties are present in the starting material, the polyCalkylene carbonate) polyahl as a consequence of the carbon di- oxide used in their preparation. The carbonate moi¬ eties are present in a ' mounts sufficient (1) to act as reaction sites when the isocyanate-modified polyCalkyl¬ ene carbonate) polyahls are advanced to higher molecu¬ lar weights by heating under reduced pressure and (2) to provide the required amount of polyester char¬ acter to the resultant polymer backbone to give useful properties such as toughness, abrasion resistance and solvent resistance. Poly(alkyleneoxy) moieties are also present in the product as a consequence of their presence in the starting material, the polyCalkylene carbonate) poly¬ ahl. Some of these moieties are present in amounts sufficient (1) to act as the source of, for example, diethylene glycol and triethylene glycol which are removed as volatile components when the isocyanate- -modified polyCalkylene carbonate) polyahls are advanced to higher molecular weights by heating under reduced pressure and C ) to provide the required amount of polyether character to the resultant polymer backbone to give useful properties such as flexibility and elongation to break. The type of alkyleneoxy moieites are also important. For example, ethyleneoxy units are important for properties such as improved antistatic characteristics while propyleneoxy or SUBSTITUTE SHEET butyleneoxy moieties are important for properties such as improved hydrolytic stability. - The residues of at least one polyisocyanate are present as a consequence of the reactions of polyisocy¬ anates with the polyCalkylene carbonate) polyahl start¬ ing materials. These polyisocyanate residues are pres¬ ent in amounts sufficient to improve properties such as modulus, strength, hardness, elongation to break and/or solvent resistance in the resultant urethane/urea polymers. The amount of polyisocyanate used to make the isocyanate-modified polyCalkylene carbonate) polyahls of this invention range from 1 to 25 weight percent based on the weight of the product. The type of poly¬ isocyanate can be an aliphatic, cycloaliphatic, arali¬ phatic, aromatic or heterocyclic polyisocyanate or a combination thereof. The choice of polyisocyanate depends on the application. An aliphatic polyisocya¬ nate is used where weatherability in the environment is important. An aromatic polyisocyanate is used, for example, in higher temperature applications. The carbon dioxide content of the isocyanate- -modified polyCalkylene carbonate) polyahl compositions can vary over a wide range to provide the desired prop¬ erty improvement over a polyether. A preferred range of carbon dioxide contents is from 5 to 30 weight percent carbon dioxide based on the weight of the isocyanate-modified polyCalkylene carbonate) polyahl product; a more preferred range is from 7 to 25 weight percent carbon dioxide and a most preferred range is from 10 to 22 weight percent carbon dioxide. SUBSTITUTE SHEET" The molecular weight of the isocyanate-modified polyCalkylene carbonate) polyahl product can vary over a wide range. Preferred molecular weights (Mn) are between 400 and 20,000; a more preferred range is from 800 to 10,000 and the most preferred range is from 1,000 to 8,000. In general, the viscosity of an isocyanate- -modified polyCalkylene carbonate) polyahl is higher 0 than the viscosity of the corresponding unmodified polyCalkylene carbonate) polyahl. This makes the iso¬ cyanate-modified polyCalkylene carbonate) polyahls more difficult to handle at higher isocyanate modi ications. 5 The isocyanate-modified polyCalkylene carbon¬ ate) polyahls of this invention are made by reacting a polyCalkylene- carbonate) polyahl with a less than stoi- chiometric amount of a polyisocyanate under conditions sufficient for reaction to occur. When the polyCalkyl¬ 0 ene carbonate) polyahl starting material has amino end groups, the isocyanate-modified polyCalkylene carbon¬ ate) polyahl product contains urea moieties in its backbone; reaction occurs at about ambient temperature c and depends on the polyisocyanate employed. Somewhat higher temperatures may be required for aliphatic poly¬ isocyanates. When the polyCalkylene carbonate) polyahl starting material has hydroxyl end groups, the isocya¬ nate-modified polyCalkylene carbonate) polyahl product 0 contains urethane moieties in its backbone; reaction occurs at temperatures from 40°C to 100°C. Higher temperatures may be required for aliphatic polyisocya¬ nates. Lower temperatures are useful when employing typical isocyanate catalysts. The molecular weight is increased by these reactions. SUBSTITUTE SHEET In a preferred embodiment, the molecular weight of the isocyanate-modified polyCalkylene carbonate) polyahl of this invention is further increased by using the processes of U.S. patent applications Serial No. 750,362, filed July 1, 1985 and Serial No. 850,788, filed April 11, 1986. These processes involve exposing the isocyanate-modified polyCalkylene carbonate) polyahl to elevated temperatures under reduced pressure conditions to split off a dialkylene glycol moiety, a triethylene glycol moiety and/or a moiety which is as volatile or more volatile than the dialkylene glycol or trialkylene glycol moiety and removing such volatile components from the reaction mass. Generally, the dialkylene glycol and/or initiator will volatilize. Depending on the degree of rectification used, and the C0 content, less volatile components may come off, su h as the trialkylene glycols. If the isocyanate- -modified polyCalkylene carbonate) polyahl starting material contains no dialkylene glycol units, the trialkylene glycol units can be removed by this process. In general, the lightest fraction which splits from the starting material will be taken off. In those embodiments wherein the polyCalkylene carbonate) polyahl is a monofunctional species, that is, where the initiator has only one active hydrogen site, under certain circumstances the initiator fragment may be more volatile than the dialkylene glycol fragment and therefore will split off and be removed more readily than the dialkylene glycol por¬ tion. When the initiator is a linear C- | _g alcohol, the C- | _g alcohol fragment will be removed before any dial¬ kylene glycol fragments will be removed. Where a lin¬ ear C-J Q or C- j i alcohol is used as the initiator, the linear C-JQ or C- ] - } alcohol is about as volatile as the SUBSTITUTE SHEET dialkylene glycol and therefore should come off at the same time. Wherein a linear C- |2 or greater alcohol is the initiator, the dialkylene glycol is more volatile and will split off. Branched alcohol initiators have somewhat different volatilities and will be split out based on its relative volatility as compared to the dialkylene or trialkylene glycol fragment. A dialkylene glycol refers herein to two alkyl- 0 ene moieties connected by an oxygen and terminated by a hydroxyl group, wherein the alkylene moieties can be substituted with a hydrocarbyl moiety. Preferred dial¬ kylene glycol moieties correspond to the formula 5 H0-C(R 2 ) 2 -C(R 2 ) 2 -0-C(R 2 ) 2 -C(R 2 ) 2 -0H wherein R 2 is as hereinbefore defined. Examples of preferred dialkylene glycols include dipropylene glycol, diethylene glycol, 1 ,2-dibutylene glycol and Q 2,3-dibutylene glycol. The volatile component can be removed by any method known in the art. Such methods include frac¬ tional distillation, fractionation, passing an inert c gas over the reaction mass so as to remove the volatile species, and any other method for removing the volatile species condensed by a water-chilled condenser as is known in the art, for example, a falling filmnstill such as a wiped film evaporator is particularly useful. 0 A preferred method of condensing the distillate is by the use of a water-chilled condenser. The majority of the volatile components present such as acetone and water, both introduced during catalysts removal, and dioxane, small quantities of which can be present due to decomposition, pass through the water-chilled condenser under the reduced pressure conditions SUBSTITUTE SHEET employed and can be condensed using a dry ice condenser. The volatile species condensed by the water-chilled condenser can be recycled to be used as initiators for the preparation of polyCalkylene carbonate) polyahls useful as starting materials in this process. The process takes place at any temperature at which the splitting off of the volatile segments oc- curs. The lower temperature limit is that temperature at which the splitting of the volatile component oc¬ curs, and the upper limit is that temperature at which the isocyanate-modified polyCalkylene carbonate) poly¬ ahl undergoes decomposition. Preferred temperatures are between 150°C and 300°C. More preferred temperatures are between 175°C and 260°C, with between 200°C and 250°C being most preferred. Pressures used in this process are those pressures at which the dialkylene glycol or species as volatile or more volatile than dialkylene glycol will volatilize at the temperatures used. Preferable pres¬ sures are atmospheric and subatmospheric, with subat- mospheric pressures being more preferable. More pref¬ erable pressures are less than 300 mm Hg (40,000 Pa), even more preferably less than 100 mm Hg (13,300 Pa), even more preferably less than 50 mm Hg (6,650 Pa), and most preferably between 10 and 30 mm Hg (1330 and 4000 Pa). The reaction time for the process is variable depending on various factors, including temperature, pressure, and the molecular weight of the desired product. At lower pressures, and higher temperatures, the time to achieve the desired molecular weight is -29- lower. The process can be run for a time sufficient to give the desired molecular weight.- - Reaction times are relatively rapid, only a few hours are required in most cases. The process is generally performed by exposing the isocyanate-modified poly(alkylene carbonate) poly¬ ahl in neat form to the processing conditions. The process can be performed in a solvent, although per- forming the process in neat form is preferred. Sol¬ vents useful include inert organic solvents with a boiling point above that of the dialkylene glycol, or the most volatile species. In a second aspect, this invention is an isocyanate-functional prepolymer composition of the novel isocyanate-modified poly(alkylene carbonate) polyahl composition of this invention formed by the reactions of an isocyanate-modified poly(alkylene carbonate) polyahl with excess polyisocyanate. The polyisocyanates suitable for these reac¬ tions have been defined hereinbefore. The isocyanate-functional prepolymers of this invention can be made by addition of excess polyisocya¬ nates to the isocyanate-modified ρoly(alkylene carbon¬ ate) polyahls of this invention or by addition of the isocyanate-modified poly(alkylene carbonate) polyahls of this invention to excess polyisocyanates. The preparation of isocyanate-functional prepolymers with prior art polyahls is well-known in the art. Examples can be found in U.S. Patents 4,108,842; 4,125,522 and 4,476,292. SUBSTITUTE SHEET In a third aspect, this invention is a novel urethane/urea polymer formed by the reactions of an isocyanate-functional prepoly er composition based on the novel, isocyanate-modified poly(alkylene carbonate) polyahls of this invention with polyahls; many of these polyahls are commonly called chain-extenders when used with isocyanate-functional prepolymers. Optionally, catalysts and a variety of additives can be included. The chain-extenders useful to make the compo¬ sitions of this Invention are preferably difunctional. Mixtures of difunctional and trifunctional chain-ex¬ tenders are also useful in this invention. The chain- -extenders useful in this invention include diols, a ino alcohols, diamines or mixtures thereof. Low molecular weight linear diols such as 1 ,4-butanediol and ethylene glycol have been found suitable for use in this invention. Other chain-extenders including cyclic diols such as 1 ,4-cyclohexanediol and 1 ,4-cyclohexane- dimethanol; aromatic ring-containing diols such as bis- hydroxyethylhydroquinone; amide or ester-containing diols or amino alcohols are useful. Aromatic diamines and aliphatic diamines are suitable chain-extenders. Examples include ethylenediamines, 1-(2-aminoisopropyl- -4-methyl-4-aminocyclohexane) , 1 ,2-propanediamine, 1,4- -butanediamine; 1 ,6-hexanediamine, diethyltoluenedi- amine and 1 ,4-bis(aminomethyl)cyclohexane. Additional examples of useful chain-extenders can be found in U.S. Patents 4,297,444; 4,202,957; 4,476,292; 4,495,309 and 4,218,543. Catalysts such as tertiary amines or an organic tin compound or other polyurethane catalysts may be used. The organic tin compound may suitably be a stan- nous or stannic"compound, such as, for example, SUBSTITUTE SHEET stannous salt of a carboxylic acid, a trialkyltin oxide, a dialkyltin dihalide and a dialkyltin oxide, wherein the organic groups of the organic portion of the tin compound are hydrocarbon groups containing from 1 to 18 carbon atoms. For example, dibutyltin dilaurate, dibutyltin diacetate, diethyltin diacetate, dihexyltin diacetate, di-2-ethylhexyltin oxide, dioctyltin dioxide, s.tannous octoate and stannous oleate, or a mixture thereof, may be used. Other catalysts include organo zinc, mercury and lead compounds. Tertiary amine catalysts include trialkylamines (e.g., trimethylamine, triethylamine) , heterocyclic amines, such as N-alkylmorpholines (e.g., N-methylmor- pholine, N-ethylmorpholine, dimethyldiaminodiethyl ether, etc.), 1 ,4-dimethylpiperazine, triethylenedi- amine, etc., and aliphatic polyamines, such as N,N,N' ,N'-tetramethyl-1 ,3-butanediamine. Optional additives include anti-foaming agents such as glycerine, an ethyl acrylate-2-ethylhexyl acry- late copolymer, dimethyl siloxane copolymers and sili- cones; antioxidants such as esters of β-(3,5-di-tert- -butyl-4-hydroxyphenyl) propionic acid with monohydric or polyhydric alcohols, for example, methanol, octadec- anol, 1 ,6-hexanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, penta- erythritol, tris-hydroxyethyl isocyanurate, and di- -hydroxyethyl oxalic acid diamide; UV absorbers and light stabilizers such as 2-(2'-hydroxyphenyl)benzo- triazoles and sterically hindered amines such as bis- -(2,2,6,6-tetramethylpiperidyl)-sebacate, bis- -( 1 , . 2,2,6,6-pentamethylpiperidyl)-sebacate, n-butyl- -3,5-di-tert-butyl-4-hydroxybenzyl malonic acid, bis- S UB S T1TUTE SHEET (2,2,6,6-pentamethylpiperidyDester, condensation prod¬ uct of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy- piperidine and succinic acid, condensation product of N,N*-(2,2,6,6-tetramethylpiperidyl)-hexamethylene diamine and 4-tert-octylamino-2,6-dichloro-1 ,3,5-s- -triazine, tris(2,2,6,6-tetramethylpiperIdyl)-nitrilo- triacetate, tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)- -1 ,2,3,4-butane-tetracarbonic acid and 1 , 1 '-( 1 ,2-eth- anediyl)-bis-(3,3,5,5-tetramethylpiperazInone) ; plas- ticizers such as, for example, phthalates, adipates, glutarates and epoxidized vegetable oils; fungicides; pigments; dyes and reactive dyes and moisture scavengers. In .addition, fillers and reinforcing materials such as chopped or milled glass fibers, chopped or milled carbon fibers and/or other mineral fibers are useful. Approximately stoichiometric amounts of the isocyanate moieties of the isocyanate-functional pre¬ polymers of this invention and the active hydrogen moi¬ eties on the polyahls are used. The equivalent ratio of isocyanate moieties to total active hydrogen moi¬ eties is between 0.95:1.00 to 1.00:1.05; more preferred is an Isocyanate:polyahl equivalent ratio of from 0.97:1.00 to 1.00:1.03; most preferred is a ratio of 1.00:1.00 to 1.00:1.03. In a fourth aspect, this invention is a novel, urethane/urea polymer formed by the reactions of the isocyanate-modified polyCalkylene carbonate) polyahls of this invention with polyisocyanates, optionally in the presence of other polyahls. Optionally, catalysts and a variety of additives can be included. Useful SUBSTITUTE SHEET -33- polyisocyanates, catalysts and additives are those that have been defined hereinbefore. Approximately stoichiometric amounts of the ,_ isocyanate moieties on the polyisocyanates and the total active hydrogen moieties on the isocyanate-modi¬ fied poly(alkylene carbonate) polyahls and other poly¬ ahls, if employed, are used. The equivalent ratio of isocyanate moieties to total active hydrogen moieties 10 is between 0.95:1.00 to 1.00:1.05; more preferred is an isocyanate:active hydrogen equivalent ratio of from 0.97:1.00 to 1.00:1.03; most preferred is a ratio of 1.00:1.00 to 1.00:1.03. The preparation of urethane/- urea polymers is well-known in the art. Examples of 15 typical reaction conditions employed can be found in U.S. Patents 4,460,715 and 4,394,491. The urethane/urea polymers of the present invention can be fabricated by any fabrication tech¬ 0 nique known in the art. Useful processes include hand casting (see, for example, U.S. Patent 4,476,292) and reaction injection molding (see, for example, U.S. Patents 4,297,444 and 4,495,309). 5 The following examples are included for illus¬ trative purposes only, and do not limit the scope of the invention or the claims. Unless otherwise stated, all parts and percentages are by weight. 0 The molecular weights and distribution are determined by size exclusion chromatography on Waters Ultrastyragel ® 1000 A (100 nm) and 10,000 A (1000 nm) columns in series using tetrahydrofuran (THF) as the mobile phase and calibrated with narrow molecular weight poly(ethylene glycol) standards. SUBSTITUTE SHEET -34- The Brookfield viscosities are all measured at ambient temperature using an LV4 spindle at the appro¬ priate spin rate. _ Distillate samples are analyzed by capillary o gas chromatography on a Hewlett-Packard 5840A unit equipped with a J&W Scientific Company DB-1 fused sil¬ ica capillary column using flame ionization detection. 1Q Example 1 A low molecular weight (Mn of 700) poly(ethyl¬ ene carbonate) polyol (960.0 g; prepared from diethylene glycol, ethylene oxide and carbon dioxide) *r - was placed in a 1-liter, 3-necked .reaction flask equipped with thermometer, overhead stirrer, dropping funnel, temperature controller and maintained under a ni.trogen atmosphere. Methylene bis(phenyl isocyanate) (108.10 g; MDI; freshly distilled) was placed in the 20 dropping funnel. The MDI was added dropwise with stirring over a 30-minute period at ambient temperature. The contents of the reactor were then heated at 80°C for 4 hours. The product (1066.5 g) was a straw-colored, viscous " liquid with a Brookfield 25 viscosity of 31,100 cps (31.1 Pa-s) at 24°C and had the following molecular weight properties: Peak = 2419; Mn = 1473; Mw = 2736; PDI 1.86. Carbon-13 nuclear mag¬ netic resonance was consistent with the expected MDI- 30 -modified poly(ethylene carbonate) polyol structure. The polyol backbone contained both carbonate (155.2 ppm) moieties and aromatic urethane C153.8 ppm) moieties. This example shows that the backbone of a polyCethylene carbonate) polyol can be modified with SUBSTITUTE SHEET 10.1 weight percent MDI to produce a hydroxy-functional polyol containing aromatic urethane moieties in its backbone. Example 2 A portion of the product from Example 1 (81.3 g) and boiling stones (0.2 g) were combined in a 100-ml, 2-necked boiling flask equipped with a thermom¬ eter, temperature controller and a simple distillation head (no column) containing a water condenser and at¬ tached to a vacuum source through a dry ice-isopropanol trap. The contents of the flask were heated at 10 mm Hg (1330 Pa) vacuum and samples are removed for molecular weight determination at various pot temperatures shown in Table I. TABLE I Pot wolecuiar weignt Sample Number Temperature (°c) Peak Mn Mw PDI 1 starting material 2419 1473 2736 1.86 2 200 2469 1510 2875 1.90 3 220 2905 1698 3477 2.05 4 230 3851 201 4375 2.17 5 240 4340 2251 5295 2.35 6 252 6781 2876 7759 2.69 SUBSTITUTE SHEET When the pot temperature reached 252°C, the system was cooled under nitrogen. The distillate col¬ lected in the water condenser accounted for 9.6 weight percent (7.8 g) of the sample charged and had the fol¬ lowing assay: 0.65 percent dioxane, 2.39 percent eth¬ ylene carbonate, 66.4 percent diethylene glycol, 16.7 percent triethylene glycol and 1.15 percent tetraethyl- ene glycol. The distillate collected in the dry ice- -isopropanol trap accounted for 0.6 weight percent (0.5 g) of the sample charged. The residue was a yel¬ low, viscous liquid accounting for 86.5 weight percent C70.3 g) of the sample charged and had a Brookfield viscosity of 426,000 cps at 24°C. This example shows that a series of urethane- -modified polyCethylene carbonate) polyols of various molecular weights can be made by this invention. Example 3 A portion of the product from Example 1 (900.8 g) and boiling stones (0.2 g) were combined in a 1-liter, 3-necked boiling flask equipped with a ther¬ mometer, temperature controller and a down draft water- -chilled condenser attached to a vacuum source through a dry ice-isopropanol trap (-78°C). The contents of the reactor were heated to a pot temperature of 230°C over a period of 2 hours at 10 mm Hg vacuum (1330 Pa). The distillate collected in the water-chilled condenser ac¬ counted for 4.5 weight percent (40.5 g) of the sample charged and had the following assay: 0.90 percent dioxane, 9.55 percent ethylene carbonate, 53.9 percent diethylene glycol, 25.2 percent triethylene glycol and 3.90 percent tetraethylene glycol. The distillate col¬ lected at -78°C accounted for 0.2 weight percent (1.9 g) SUBSTITUTE SHEET of the sample charged and had the following assay: 45.0 percent dioxane, 36.5 percent acetone and 6.6 percent water. The residue which was a light amber, viscous liquid containing 10.7 weight percent MDI chemically incorporated into the polyol backbone, represented 94.8 weight percent (853.5 g) of the sample charged and had a Brookfield viscosity of 106,400 cps (106.4 Pa-s)at 24°C. The Mn by end group (OH) titration was 1560. The molecular weight by size exclusion chromatography was: Peak = 3484; Mn = 1912; Mw = 3954; PDI = 2.07. Tg = -33°C. This example shows a scale-up of a urethane- -modified poly(ethylene carbonate) polyol. Example 4 The low molecular weight pol (ethylene carbon¬ ate) polyol used in Example 1 (1001.7 g) was placed in the same reaction setup as used in Example 1. MDI (60.1 g, freshly distilled, 125M) was placed in the dropping funnel and added dropwise with stirring over a 15-minute period at ambient temperature. The contents of the reactor were then heated to 80°C for 3 hours. The product (1061.5 g) was a straw-colored, viscous liquid with a Brookfield viscosity of 9210 cps (9.21 Pa-s) at 25°C and had the following molecular weight properties: Peak = 1677; Mn = 1117; Mw = 1937; PDI = 1.74. A portion of the product formed above (913.1 g) and boiling stones (0.2 g) were combined in the same equipment used in Example 3. The contents of the reac¬ tor were heated to a pot temperature of 230°C over a period of 2 hours at 10 mm Hg (1330 Pa) vacuum. The SUBSTITUTE SHEET -38- distillate collected in the water-chilled condenser accounted for 9.1 weight percent (82.7 g) of the sample charged and had the following assay: 0.69 percent dioxane, 6.11 percent ethylene carbonate, 50.4 percent diethylene glycol, 29.4 percent triethylene glycol and 5.60 percent tetraethylene glycol. The distillate collected at -78°C accounted for 0.3 weight percent (2.6 g) of the sample charged and had the following assay: 45.7 percent dioxane, 36.4 percent acetone and 6.1 0 percent water. The residue was a light amber, viscous liquid containing 6.28 weight percent MDI chemically incorporated into the polyol backbone, represented 90.2 weight percent (823.4 g) of the sample charged and has ,- a Brookfield viscosity of 63,300 cps (63.3 Pa-s) at 24°C. The Mn by end group (OH) titration was 1752. The mo ' lecular weight by size exclusion chromatography was: Peak = 4089; Mn = 2103; Mw = 4463; PDI = 2.12. Carbon- -13 nuclear magnetic resonance indicated that the 0 polyol backbone contained both carbonate (155.2 ppm) moieties and aromatic urethane (153.8 ppm) moieties. Tg = -36°C. Example 5 5 The low molecular weight poly(ethylene carbon¬ ate) polyol used in Example 1 (1001.9 g) was placed in the same reaction setup as used in Example 1. TDI (61.0 g, 80 percent toluene-2,4-diisocyanate and 20 0 percent toluene-2,6-diisocyanate) was placed in the dropping funnel and added dropwise with stirring over a 15-minute period at ambient temperature. The contents - of the reactor were then heated to 80°C for 3 hours. The product (1062.9 g) was a straw-colored viscous liq¬ uid -with a Brookfield viscosity of 13,600 cps (13.6 Pa-s) at 24°C and had the following molecular weight SUBSTITUTE SHEET -39- properties: Peak = 2014; Mn = 1189; Mw = 2123; PDI = 1.79. A portion of the product formed above (912.6 g) [ . and boiling stones (0.2 g) were combined in the same equipment used in Example 3- The contents of the reac¬ tor were heated to a pot temperature of 230°C over a period of 2 hours at 10 mm Hg (1330 Pa) vacuum. The distillate collected in the water-chilled condenser 10 accounted for 8.0 weight percent (73.1 g) of the sample charged and had the following assay: 7.00 percent ethylene carbonate, 54.9 percent diethylene glycol, 26.8 percent triethylene glycol and 4.30 percent tetraethylene glycol. The distillate collected' at -78°C 15 accounted for 0.2 weight percent (2.0 g) of the sample charged and had the following assay: 31.7 percent dioxane, 44.4 percent acetone and 10.1 percent water. The residue was a light amber, viscous liquid 0 containing 6.29 weight percent TDI chemically incorporated into the polyol backbone, represented 91.3 weight percent (832.8 g) of the sample charged and had a Brookfield viscosity of 101,800 cps (101.8 Pa-s) at 24°C. The Mn by end group (OH) titration was 1820. The 5 molecular weight by size exclusion chromatography was: Peak = 3700; Mn = 2024; Mw = 4370; PDI = 2.16. Carbon- -13 nuclear magnetic resonance indicated that the polyol backbone contained both carbonate (155.2 ppm) moieties and aromatic urethane (153.8 ppm) moieties. 0 Tg = -30°C. Example 6 The low molecular weight poly(ethylene carbon¬ ate) polyol used in Example 1 (799.0 g) was placed in the same reaction setup as used in Example 1 and heated SUBSTITUTE SHEET to 80°C. MDI (171.0 g, freshly distilled, 125M) was placed in the dropping Tunnel and added dropwise with stirring over a 30-minute period. The contents of the reactor were held at 80°C for 2 hours after the addition 5. was complete. The product was a straw-colored, viscous liquid with a Brookfield viscosity of 898,000 cps (898 Pa-s) at 25°C, contained 18.0 weight percent MDI chemically incorporated into the polyol backbone, Tg = -22°C, and had the following molecular weight 10 properties: Peak = 5208; Mn = 2602; Mw = 5373 and PDI = 2.06. Example 7 - Preparation of an Isocyanate-Functional Prepbly er T5 A portion of the 10.7 weight percent MDI-modi- fied poly(ethylene carbonate) polyol prepared in Exam¬ ple 3 C69.63 g) and one drop Cabout 15 mg) of benzoyl chloride were placed in a 100-ml resin pot reactor 20 equipped with thermometer, overhead stirrer, temp¬ erature controlled at 80°C with a water bath and maintained under a nitrogen atmosphere. Freshly dis¬ tilled 4,4'-methylene bis(phenyl isocyanate) (MDI; 45.1 g) was added to the reactor. The reactor was 25 maintained at 8θ Q C for one hour after the MDI addition; the resultant isocyanate-functional prepolyraer was then analyzed for isocyanate content (ASTM D-2638-74) and found to be 9.77 weight percent NC0. 30 Example 8 - Preparation of a Polyurethane Elastomer The isocyanate-functional prepolymer of Example 7 was thoroughly degassed under vacuum and quickly poured into a 150-ml plastic cup (102.44 g). One drop (about 15 mg) of a catalyst solution was added (10.0 weight percent dibutyltin dilaurate in a 1200 molecular SUBSTITUTE SHEET weight poly(propylene glycol). 1 ,4-Butanediol (10.20 g, distilled from calcium hydride) was thoroughly degassed under vacuum and added quickly to give a 105 index (molar ratio of isocyanate:polyol is 1.05:1). The mixture was stirred rapidly for 48 seconds and then poured into a preheated mold, 6.0" x 6.0" x 0.125" (150 mm x 150 mm x 3.2 mm). The sample was cured at 121°C (250°F) for one hour. An elastomeric urethane plaque was obtained upon demolding. The part was allowed to stand for 14 days at ambient conditions; then physical properties were determined (see Table II). Example 9 - Preparation of an Isocyanate-Functional Prepolymer A prepolymer was made from the 6.28 weight percept MDI-modified poly(ethylene carbonate) polyol prepared in Example 4 (70.67 g)-, freshly distilled MDI (45.1 g) and one drop of benzoyl chloride (15 mg) using the same equipment and procedure as in Example 7. The prepolymer had a 10.00 weight percent NC0 content. Example 10 - Preparation of a Polyurethane Elastomer The isocyanate-functional prepolymer of Example 9 (104.23 g), one drop of catalyst solution and 1,4-bu- tanediol (10.62 g, 105 index) were used to form a plaque using the same procedure and conditions as in Example 8. The physical properties are given in Table II. Example 11 - Preparation of an Isocyanate-Functional Prepolymer A prepolymer was made from the 6.29 weight per¬ cent TDI-modified poly(ethylene carbonate) polyol SUBSTITUTE SHEET prepared in Example 5 (7 .02 g), freshly distilled MDI (44.0 g) and one drop of benzoyl chloride (about 15 mg) using the same equipment and procedure as in Example 7. The prepolymer had a 9.90 weight percent NC0 content. Example 12 - Preparation of a Polyurethane Elastomer The isocyanate-functional prepolymer of Example 11 (104.02 g), one drop of catalyst solution and 1,4- 10 -butanediol (10.50 g, 105 index) were used to form a plaque using the same procedure and conditions as in Example 8. The physical properties are given in Table II. 15 20 25 n 30 SUBSTITUTE SHEET TABLE II Selected Polymer Properties Polymer Flexural® Wt % Modifier Wt % NCO in Density© Hardness , Notched From Modulus in Polyol Prepolymer g/cc (kq/m 3 l (Shore D) Izod φ Example psi (GPa) (Λ G 0 10.00 1.27 (1270) 48 10,600 (0.073) Ho break CO 10.7% MDI 9.77 1.27 (1270) 60 13,900 (0.096) No break H ∑i 10 6.28% MDI 10.00 1.27 (1270) 51 10,200 (0.071) No break C H 12 6.29% TDI 9.90 1.27 (1270) 58 10,400 (0.072) No break m (A n m -4 TABLE II (continued) Selected Polymer Properties Tensile Stress at % Elongation*-" Solvent Resistance ® psi (MPa) (% Wt Gain; 6 days @ Ambient ω %E1ongation Temperature) G - at Break ® W ω 100% 200% 300% At Break Water Toluene Methanol MEK a H 1440 (9,9) 1720 (11.86) 1970 (13.6) 2260 (15.6) 460 4.6 11.7 11.7 30.9 C 2230 (15.4) 2610 (18.0) 2950 (20.3) 3470 (23.9) 530 2.8 3.7 11.5 29.4 PI 1730 (11.9) 2160 (14.9) 2520 (17.4) 4120 (28.4) 770 3.5 5.6 11.7 28.5 0) 1780 (12.3) 2190 (15.1) 2540 (17.5) 3860 (26.6) 700 3.8 5.2 12.5 28.6 PI -I ώ Determined by weight change on water immersion (Experimental Mechanics of Fiber Reinforced Composite Materials by J. M. Whitney, O. M. Daniel and R. B. Pipes; Chapter 4.2,1, p 154). ASTM E-140 S) ASTM D-790 it) ASTM D-256 <s ASTM D-638 ASTM D-638 (D Determined by measuring the weight gain of a sample immersed in a solvent at ambient temperature (static) for 6 days. It is understood that various other modifi¬ cations will be apparent also and can readily be made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth here¬ in, but rather that the claims be construed as encom¬ passing all the features of patentable novelty which reside in the present invention, including all the features which would be considered as equivalents thereof by those skilled in the art to which this invention pertains. SUBSTITUTE SHEET

Claims: 1. An isocyanate-modified poly(alkylene carbonate) polyahl which is a polymer comprising (1) a backbone having (a-) the residue of at least one polyahl initiator; (b) the residue of at least one polyiso¬ cyanate; (c) a plurality of poly(alkyleneoxy) . moieties; Cd) a plurality of polyCalkylene carbonate) moieties; and (2) a plurality of active, hydrogen " end groups, in an amount sufficient to act as reaction sites when the isocyanate-modified polyCalkylene carbonate) poly¬ ahls are advanced to higher molecular weights by heat¬ ing under reduced pressure and to provide the required amount of polyester character to the resultant polymer backbone to give useful properties such as toughness, abrasion resistance and solvent resistance. 2. The isocyanate-modified polyCalkylene carbonate) polyahl of Claim 1 wherein the isocyanate is selected from the group consisting of toluene diisocya- SUBSTITUTE SHEET nate, methylene bis(4-phenylisocyanate) and quasi- and prepolymers of methylene bis(4-phenylisocyanate) . 3. The isocyanate-modified polyCalkylene carbonate) polyahl of Claim 1 wherein the polyCalkyl- eneoxy) moieties are polyCethyleneoxy) moieties, poly- (propyleneoxy) moieties or combinations thereof and the polyCalkylene carbonate) moieties are polyCethylene carbonate) moieties, polyCpropylene carbonate) moieties, polyCbutylene carbonate) moieties or combinations thereof. 4. The isocyanate-modified polyCalkylene carbonate) polyahl of Claim 1 wherein the weight per- cent of isocyanate used to make the modified polyahl is from 1 to 25 percent. 5. The isocyanate-modified polyCalkylene carbonate) polyahl of Claim 1 which is a random polymer corresponding to the formula O R 1 {XCC(R) 2 C(R 2 ) 2 0 y (C(R 2 ) 2 -C(R 2 ) 2 OCQ^{MX'} s (R 1 (XA) n . 1 ) z -H} n II wherein R' is separately in each occurrence an n-valent n hydrocarbon radical or hydrocarbon radical which can contain one or more heteroatoms of 0, N or S; R 2 is separately in each occurrence hydrogen, halogen, a nitro group, a cyano group, a C- | _20 hydrocarbyl group or a C- | _2 Q hydrocarbyl group sub¬ stituted with one or more halo, cyano, nitro, thio¬ alkyl, tert-amino, alkoxy, aryloxy, aralkoxy, car- SUBSTITUTE SHEET bonyldioxyalkyl, carbonyldioxyaryl, carbonyldioxy- aralkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxy¬ carbonyl, alkylcarbonyl, arylcarbonyl, aralkylcar- bonyl, alkylsulfinyl, arylsulfinyl, aralkylsul- finyl, alkylsulfonyl, arylsulfonyl, or aralkylsul- fonyl group; M is separately in each occurrence the residue of an aliphatic, cycloaliphatic, araliphatic, aro- matic or heterocyclic polyisocyanate or a combina¬ tion thereof; X is separately in each occurrence S, 0, NH, 0 0 0 if » n -CO- , -0C0- , or -0CNH- ; X* is separately in each occurrence S, 0 or NH; A is separately in each occurrence 0 If C(R 2 ) 2 C(R 2 ) 2 -0CQ χ , C(R 2 ) 2 C(R 2 ) 2 0t y , combinations thereof or a covalent bond; Q is separately in each occurrence 0, S or NH provided that all carbonate moieties are internal because terminal carbonate moieties are unstable and form OH moieties by the elimination of C0 2 ; n is separately in each occurrence an integer of from 1 to 25; s is separately in each occurrence an integer of from 1 to 5; SUBSTITUTE SHEET x is separately in each occurrence an integer of from 1 to 40; y is separately in each occurrence an integer of from 1 to 120; and z is separately in each occurrence an integer of from 0 to 5. 6. The isocyanate-modified poly(alkylene carbonate) polyahl of Claim 5 wherein M is the residue of a polyisocyanate selected from the group consisting of toluene diisocyanate, methylene bis(4-phenylisocyanate) , quasi- and pre¬ polymers of methylene bis(4-phenylisocyanate) , and combinations thereof; X is oxygen; x is separately in each occurrence an integer from 2 to 10; y is separately in each occurrence an integer from 5 to 15; and z is an integer from 0 to 2, provided that the ratio of y to x is from 1:1 to 3:1. 7. The isocyanate-modified poly(alkylene carbonate) polyahl of Claim 6 wherein R' is aliphatic or cycloaliphatic hydrocarbon containing one or more oxygen, nitrogen, or sulfur moieties; SUBSTITUTE SHEET ~ R 2 is hydrogen, C- | _ 2 Q alkyl, C- | _ 20 haloalkyl, c 1-20 alkenyl or phenyl; X is S, 0 or NH; and n is an integer from 1 to 10. 8. The isocyanate-modified poly(alkylene carbonate) polyahl of Claim 7 wherein 10 1 is an n-valent alkane or cycloalkane, or an n-valent alkane or cycloalkane containing one or more oxygen, nitrogen or sulfur moieties; R 2 is hydrogen, methyl or ethyl; 15 X is 0; X I is 0; n is an integer from 1 to 5; and ' 20 s is an integer from 1 to 3. 9. The isocyanate-modified polyCalkylene carbonate) polyahl of Claim 1 which is a random polymer 25 corresponding to the formula 0 If {CR 3 t x CC0) y fCCR 2 ) 2 C(R 2 ) 2 0) z (MX') s -H} p wherein 30 R is R 4 -X'n : R 2 is separately in each occurrence hydrogen, halogen, a nitro group, a cyano group, a C^_ 2Q hydrocarbyl group or a C- ] _ 20 hydrocarbyl group substituted with one or more halogen, cyano, nitro. SUBSTITUTE SHEET thioalkyl, tert-amino, alkoxy, aryloxy, aralkoxy, carbonyldioxyalkyl, carbonyldioxyaryl, carbonyldi- oxyaralkyl, alkoxycarbonyl, aryloxycarbonyl, aral- koxycarbonyl, alkylcarbonyl, arylcarbonyl, aralkyl- carbonyl, alkylsulfinyl, arylsulfinyl, aralkylsul- finyl, alkylsulfonyl, arylsulfonyl, or aralkylsul- fonyl group; R3 is separately in each occurrence an n-valent hydrocarbon radical or hydrocarbon radical which contains one or more heteroatoms of 0, N or S; M is separately in each occurrence the residue of an aliphatic, cycloaliphatic, araliphatic, aro- matic or heterocyclic polyisocyanate or a combina¬ tion thereof; X' is 0, S or NH; n is separately in each occurrence an integer of from 1 to 25; p is an integer of 1 or greater; s is separately in each occurrence an integer of 1 to 5; x is 1 ; y is separately in each occurrence 1 to 40; and z is separately in each occurrence 1 to 100. 10. An isocyanate-functional prepolymer com¬ prising the reaction product of at least one isocya¬ nate-modified polyCalkylene carbonate) polyahl of Claim 1 and at least one organic polyisocyanate; the propor- SUBSTITUTE SHEET tion of said isocyanate-modified polyCalkylene carbon¬ ate) polyahl to said polyisocyanate being such that all polyahl moieties are reacted with isocyanate moieties and Isocyanate moieties are present in excess. 11. A urethane/urea polymer comprising the residue of CD at least one isocyanate-functional prepoly¬ mer of Claim 10 and the residue of at least one polyahl selected from the group consisting of aromatic, ali¬ phatic, arylaliphatic, alkylaromatic and cycloaliphatic polyamines, polymercaptans and polyfunctional hydroxyl compounds, or (2) one or more of the isocyanate-modified polyCalkylene carbonate) polyahls of Claim 1 and one or more organic polyisocyanates. SUBSTITUTE SHEET

Inventors: HARRIS ROBERT F, HARRIS, ROBERT, F.
Applicants: DOW CHEMICAL CO, THE DOW CHEMICAL COMPANY
Application year: 1988
Main classification: C07C69
IPC codes: C07C265, C08G18