Process for preparing polyalkylene glycol alkyl or haloalkyl polyphosphonates

Polyalkylene glycol alkyl or haloalkyl polyphosphonates having the idealized formula: ##STR1## wherein R is a polyalkylene glycol residue, R' is alkyl or haloalkyl and n is 1-100, are prepared by transesterifying a tertiary phosphite with a polyalkylene glycol and rearranging the resultant polyalkylene glycol alkyl or haloalkyl polyphosphite to a polyalkylene glycol alkyl or haloalkyl phosphonate by the action of heat and an Arbuzov rearrangement catalyst.

BACKGROUND OF THE INVENTION 
In the polyurethane field, increased interest is being shown in compounds 
which can be added to the polyurethane polymers to act as flame retardant 
agents. Particular interest is being shown in compounds which have 
functional groups reactive with the polyol or polyisocyanate used in 
preparing the polyurethane so that the flame retardant agent can be 
copolymerized into the polymer chain. One such group of reactive flame 
retardants are the polyalkylene glycol phosphites such as those described 
in U.S. Pat. No. 3,009,939. However, these materials, due to their high OH 
number and crosslinking tendency, are unsuitable for use in flexible 
urethane foams. In U.S. Pat. Nos. 3,081,331 and 3,142,651, there is 
disclosed a method of forming polyalkylene glycol polyphosphites having up 
to 10 phosphite groups in the polymer chain by reacting a trialkyl 
phosphite with a polypropylene glycol in a molar ratio of 2.1 to 2.5 moles 
of glycol per mole of phosphite. These materials are also unsuitable for 
use in flexible urethane foams as a result of their high OH numbers and 
their tendency to crosslink. 
Another attempt at employing reactive flame retardants, described in U.S. 
Pat. Nos. 3,142,651 and 3,092,651, involves the use of polypropylene 
glycol poly-hydrogenphosphonates produced by a thermal polymerization. 
Likewise, polyalkylene glycol hydrogen polyphosphonates have also been 
produced by transesterifying a secondary hydrogen phosphonate with a 
polyalkylene glycol according to the procedure outlined in British Pat. 
Nos. 796,446 and 1,011,118. However, many of these materials have 
relatively high acidity, causing them to react with and thereby deactivate 
the catalyst systems generally used in the formation of polyurethane 
polymers such as, for example, tertiary amine compounds. The former method 
has the additional drawback of contamination of the product by the 
alkylene glycol by-product, which contaminant is not easily removed. 
In order to increase the flame retardancy of some of the above described 
phosphorus compounds, which have low phosphorus content, the prior art has 
attempted to incorporate various halogen containing substituents into the 
above described molecules. Thus, U.S. Pat. Nos. 3,159,605 and 3,167,575, 
describe the reaction of halogenated methanes with these compounds. 
Likewise, U.S. Pat. Nos. 3,131,206 and 3,328,493, describe the reaction of 
chloral with them. However, these materials, like their precursors, have 
many drawbacks. In particular, these products have high OH numbers and low 
phosphorus content thereby rendering them less suitable as flame 
retardants in flexible urethane foams. 
In addition to these above-mentioned prior art references, Review In 
Macromolecular Chemistry, Vol. II, N.Y.C. 1967, discloses that 
polyalkylene glycol alkyl phosphonates have been prepared by reacting an 
alkyl phosphonic acid dichloride with a polyalkylene glycol. This 
procedure was originally reported by Korshak et al, in Vzsokomolekuylarnye 
Soedineniya 2, 427-32 (1960). In a subsequent article by Tormosina et al, 
Khim. Khim. Tekhonol. 1968, 31-41, the polyalkylene glycol alkyl 
phosphonates prepared by this route are disclosed as containing 
unhydrolyzed chlorine and being too acidic for use in polyurethane foam. 
Furthermore, Korshak et al, Izv. Akad. Nauk. SSSR, Otd. Khim. Nauk. 
1963(6), 1095-1100, disclose the preparation of polyalkylene glycol alkyl 
phosphonates by transesterifying dimethylmethylphosphonate with diethylene 
glycol. The product, however, is disclosed as being characterized with an 
acid number of from 240 to 400 mg. of KOH/gm. of sample and accordingly is 
also unsuitable for use in polyurethane foam. 
In co-pending U.S. applications Ser. No. 166,289 filed July 26, 1971 and 
issued as U.S. Pat. No. 3,789,290 on Mar. 19, 1974 and Ser. No. 86,313 
filed Nov. 2, 1970 and issued as U.S. Pat. No. 3,819,750 on June 25, 1974, 
there are disclosed novel polyalkylene glycol vinyl phosphates and novel 
mixed polyalkylene glycol vinyl phosphates and phosphites which are 
prepared by reacting a halogenated carbonyl compound with a polyalkylene 
glycol alkyl polyphosphite. While these vinyl phosphonates yield 
polyurethane foam having excellent flame retardant and physical 
characteristics, they have recently been found to impart a slight odor to 
the foam which may be considered objectionable. 
SUMMARY OF THE INVENTION 
Accordingly, it is one object of the present invention to provide novel 
polyalkylene glycol alkyl or haloalkyl polyphosphonates which are suitable 
as flame-retardants. 
Another object of this invention is to provide polyalkylene glycol alkyl or 
haloalkyl polyphosphonates suitable as flame retardants for urethane 
foams, and in particular flexible and rigid urethane foams. 
A further object of the present invention is to provide polyalkylene glycol 
alkyl or haloalkyl polyphosphonates which, while imparting excellent 
flame-retardancy to urethane foam, are further characterized by superior 
chemical and physical properties, such as, for example, stability and low 
acidity, so as to yield foams having good color, good appearance, no odor 
and generally good physical properties. 
A further object of this invention is to provide urethane foams having 
incorporated therein these novel polyalkylene glycol alkyl or haloalkyl 
polyphosphonates. 
A still further object of the present invention is to provide novel 
processes for the preparation of these polyalkylene glycol alkyl or 
haloalkyl polyphosphonates. 
Further advantages of the present invention will become obvious from a 
reading of the disclosure which follows hereinafter. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
It has now been discovered that by heating certain polyalkylene glycol 
alkyl polyphosphites in the presence of an alkyl halide, there is obtained 
polyalkylene glycol alkyl polyphosphonates which are polymers being 
particularly characterized by their excellent flame retardant properties 
and low acidity. In addition, the present polyalkylene glycol alkyl 
polyphosphonates are characterized by low OH numbers, lack of tendency to 
gel initially or crosslink in the final foamed product, high stability 
during and subsequent to the foam forming process, and the overall general 
ability to yield urethane foams which have superior flame retardancy and 
excellent physical properties, such as the substantial lack of scorch, 
discoloration, odor and other undesirable properties. 
The polyalkylene glycol alkyl polyphosphonates of the present invention can 
be represented by an idealized formula as follows: 
##STR2## 
wherein R is a polyalkylene glycol residue; R' is alkyl or haloalkyl and n 
is a number in the range of from about 1 to 100, and preferably from about 
5 to 20. Preferably, R' is C.sub.1 -C.sub.10 alkyl or C.sub.1 -C.sub.10 
haloalkyl. Haloalkyl is intended to include for example, chloromethyl, 
bromomethyl, chloroethyl, bromoethyl, dichloropropyl, and the like. Most 
preferably, however, R' is methyl. The term polyalkylene glycol residue, 
designated by R, is meant to define that portion remaining after two 
hydroxyl groups have been removed from a polyalkylene glycol having the 
formula: 
##STR3## 
wherein R" is an alkylene group of 2 to about 20 carbon atoms, which is 
straight chained, branch chained, or a mixture thereof, with the proviso 
that at least two carbon atoms separate successive oxygen atoms, and x 
designates the number of repeating alkylene ether units and is normally 2 
to about 20. For the purposes of the present invention, R is Formula I 
above, is most preferably a diethylene glycol residue. 
As indicated above, Formula I represents an idealized structure of the 
final products of the present invention. It is clear to one skilled in the 
art that as a result of the polymeric nature of these polyalkylene glycol 
alkyl polyphosphonates of the present invention and their method of 
preparation, these products are complex mixtures. Thus, for example, these 
mixtures will include in addition to the hydroxy terminated polymers, as 
represented by the idealized structure of Formula I above, a statistical 
quantity of polymeric product wherein the terminal hydroxy groups are 
either partially or fully replaced by 
##STR4## 
groups wherein R' is as defined above. Furthermore, the polymer products 
of the present invention will also include a statistical quantity of 
polymeric product wherein R' of Formula I above, is replaced by an R 
group, also as defined above, and in turn the alkyl or haloalkyl 
phosphonate condensates thereof. Therefore, it is to be understood that 
the present invention as particularly encompassed by the structure of 
Formula I above, is obviously intended to include these polymeric 
materials individually as well as in combination. 
The compounds of the present invention are prepared by heating a 
polyalkylene glycol alkyl or haloalkyl polyphosphite which has an 
idealized formula as follows: 
##STR5## 
wherein R, R' and n are as described above, in the presence of an alkyl or 
aralkyl halide. This polyphosphite of Formula II above, is formed by 
transesterifying a tertiary phosphite with a polyalkylene glycol in a 
molar ratio of from about 0.8 to about 1.5 and preferably from about 0.8 
to about 1.2 moles of phosphite per mole of glycol. 
The preparation of these polyalkylene glycol polyphosphites of Formula II 
is disclosed in the above-noted co-pending applications and in addition 
are disclosed and claimed in co-pending U.S. application Ser. No. 166,295 
filed on July 26, 1971, by Silvio L. Giolito and abandoned in favor of 
continuation-in-part application Ser. No. 322,595, filed Jan. 10, 1973 
which was abandoned in favor of continuation application Ser. No. 483,606 
filed June 27, 1974. 
The tertiary phosphite used to prepare these polyalkylene glycol alkyl or 
haloalkyl polyphosphite starting materials of Formula II has the general 
formula: 
##STR6## 
wherein each R' is as defined above. Thus, illustrative of the tertiary 
phosphites which can be employed are the following: trimethyl phosphite, 
triethyl phosphite, tripropyl phosphite, tributyl phosphite, trioctyl 
phosphite, dimethyl ethyl phosphite, diethyl methyl phosphite, 
tris(chloroethyl) phosphite, tris(2-chloropropyl) phosphite, 
tris(dichloropropyl) phosphite, and the like. Trimethyl and triethyl 
phosphite are particularly preferred, with trimethyl phosphite being most 
preferred. 
The above described tertiary phosphite is transesterified with a 
polyalkylene glycol having the formula: 
##STR7## 
wherein R" and x are as described above. Illustrative of the polyalkylene 
glycols which can be employed in the present invention are the following: 
diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene 
glycol, tributylene glycol, polyethylene glycols, polypropylene glycols 
wherein the average number of ether units is 14, trihexylene glycol and 
the like. Particularly preferred glycols are diethylene glycol, 
dipropylene glycol and tripropylene glycol, with diethylene glycol being 
most preferred. It is understood that the propylene glycols can be 
primary, secondary, or mixtures thereof. 
In order to form the polyphosphite starting material of Formula II above, 
the tertiary phosphite and the polyalkylene glycol must be reacted in 
critical proportions. Thus, the tertiary phosphite should be present in an 
amount from about 0.8 to about 1.5 moles per mole of the glycol. The 
preferred range for this preparation is from about 1 to about 1.2 moles of 
phosphite per mole of glycol. If the glycol is reacted in quantitites 
substantially greater than about 1 to 1 with the phosphite, the product 
will contain primarily the undesirable mono, di, tri and tetraphosphites 
and, more importantly, will have a substantial amount of free 
hydroxyalkyleneoxyalkylene groups attached to the phosphite group. 
Where trimethyl phosphite and diethylene glycol are utilized to prepare the 
polyphosphite of Formula II, it now has been found for the purposes of 
this invention, that it is most preferred to employ 1.1 moles of phosphite 
to 1 mole of glycol. 
The above disclosed transesterification reaction is normally conducted by 
mixing the phosphite and glycol in the presence of any of the well known 
transesterification catalysts. Particularly useful catalysts are the 
alkali metal alcoholates and phenolates such as sodium methylate, sodium 
decylate, sodium phenolate, and the like. These catalysts are normally 
employed in an amount from about 0.1 to about 10 percent, by weight, of 
the entire reaction mixture. Again, with particular regard to the 
transesterification reaction between trimethyl phosphite and diethylene 
glycol it now has been found that no catalyst is necessary, although, 
obviously if desired, one may be employed. The reaction temperature should 
initially be kept below the boiling point of the lowest boiling reactant 
in order to avoid the loss of that reactant. Although the reaction can be 
conducted at room temperature, i.e., 20.degree. C., it is preferred to 
conduct it as close to the upper limit as possible in order to increase 
the rate of reaction. Thus, in the case where trimethyl phosphite is 
employed as the tertiary phosphite, the reaction temperature is preferably 
within the range of 60.degree. to 110.degree. C. and should not be allowed 
to rise above 110.degree. C. until at least one R' group on each of the 
phosphite molecules has been replaced with a polyalkylene glycol. This can 
normally be determined by monitoring the amount of methanol which has been 
evolved. 
While the reaction can be run to completion at these temperature ranges, it 
has been found to be advantageous at times to raise the temperature after 
this initial replacement of one of the R' groups on the starting phosphite 
up to a limit of about 150.degree. C. and most preferably up to about 
120.degree. C. As stated above, the point at which the temperature should 
be raised can be determined by monitoring the amount of by-product alkanol 
produced. Thus, when one mole of trimethyl phosphite is being 
transesterified, the reaction temperature can be raised after one mole of 
methanol has been evolved. The transesterification is completed when two 
moles of methanol have been evolved. The degree of polymerization of the 
polyphosphite can be controlled to an extent by varying the time of the 
reaction. Furthermore, the polymer length can be monitored by measuring 
the viscosity buildup during the reaction according to well known 
techniques. 
The transesterification reaction can optionally be carried out in the 
presence of an inert solvent, however, such solvent is not required for 
the practice of the present invention. The term inert solvent is meant to 
designate any solvent which does not react with the starting materials or 
products of the present invention. Suitable solvents include the alkylated 
benzenes such as ethyl benzene, diethyl benzene, toluene, the xylenes, and 
substituted benzenes such as o-dichlorobenzene, chlorobenzene, anisole and 
the like. 
The polyalkylene glycol alkyl or haloalkyl polyphosphite produced by the 
process described above and represented by Formula II, is then heated in 
the presence of an Arbuzov rearrangement catalyst whereby a rearrangement 
is effected and the polyalkylene glycol alkyl or haloalkyl polyphosphonate 
of Formula I above is formed. This rearrangement reaction may be carried 
out over a wide temperature range. Generally, temperatures from about 
160.degree. to about 230.degree. C. are employed, with the preferred range 
being from about 165.degree. to about 200.degree. C. Although, any Arbuzov 
rearrangement catalyst may be employed, the alkyl halides and aralkyl 
halides are preferred. Illustrative of these are, for example, methyl 
iodide, ethyl iodide, methyl bromide, methyl chloride, butyl iodide, butyl 
chloride, aryl iodide, nonyl bromide, octyl iodide, benzyl bromide, benzyl 
iodide, chloromethylnapthalene, triphenylbromomethane, and the like. 
Methyl iodide is most preferred. Among other Arbuzov rearrangement 
catalysts are included elemental iodide and alkali metal halides, such as 
sodium iodide, potassium iodide, potassium fluoride, sodium bromide, 
lithium iodide, and the like. Any catalytically effective amount of the 
catalyst may be employed and generally is in the range of from about 0.05% 
to about 5% by weight. Preferably from about 0.1% to about 0.2% of 
catalyst is used. 
Similar to the transesterification reaction described above, the 
rearrangement of the polyalkylene glycol alkyl or haloalky polyphosphite 
can optionally be carried out in the presence of an inert solvent, 
however, such solvent is not required for the practice of the present 
invention. Thus, the same solvent as employed during the 
transesterification reaction or a different solvent may be used during the 
rearrangement reaction. Suitable solvents include the alkylated benzenes 
such as ethyl benzene, diethyl benzene, toluene, the xylenes and 
substituted benzenes such as o-dichlorobenzene, chlorobenzene, anisole and 
the like. Furthermore, in performing the rearrangement reaction, the 
catalyst may be added all at once or in increments to the polyalkene 
glycol alkyl or haloalkyl polyphosphite intermediate. Moreover, if a 
solvent is being employed, a mixture of said solvent and catalyst may be 
added in increments. When a solvent is being employed, the rearrangement 
is generally completed in from about 2 to about 20 hours, whereas the 
reaction is completed in from about 5 minutes to about one hour in the 
absence of a solvent, depending upon the temperature being employed. The 
final product, i.e. the polyalkylene glycol alkyl polyphosphonate is 
essentially neutral and generally does not have an acid number in water in 
excess of 15 miligrams of KOH per gram of sample (in water). Accordingly, 
there is no need to neutralize the polyalkylene glycol alkyl or haloalkyl 
polyphosphonates prepared according to the present invention. However, if 
desirable, the polyalkylene glycol alkyl or haloalkyl polyphosphonate may 
be further neutralized by employing any of the conventional means to do 
so, such as treatment with ethylene oxide, propylene oxide, 
epichlorohydrin and the like. 
The novel polyalkylene glycol alkyl or haloalkyl polyphosphonates of the 
present invention are particularly characterized by their ability to 
copolymerize with polyisocyanates employed in forming polyurethanes, by 
their relatively low OH numbers and low acidity, by their high phosphorus 
content, and by their high flame retardant and stabilized characteristics 
especially in the final foams. These compounds can completely replace the 
polyols normally employed in forming the urethane foams or they can be 
used in combination with the polyols, thereby yielding foams with greatly 
improved flame resistance. Since they react in the foam forming process, 
their residues are chemically bonded into the foam, thereby giving them 
high performance such as durability, even upon high temperature aging or 
after water or solvent extraction. As stated above, the acid numbers in 
water of the polyalkylene glycol alkyl or haloalkyl polyphosphonates of 
the present invention are generally in the range of from essentially 
neutral to about 15 milligrams of KOH per gram of sample, and most usually 
from essentially neutral to about 2 milligrams of KOH per gram of sample. 
This lack of or low acidity, in contrast to the higher acidity of prior 
art compounds, makes the compounds of the present invention essentially 
unreactive toward the polymerization catalysts employed in producing the 
polyurethane foams. As mentioned above, the present compounds also have 
relatively lower OH numbers as compared to the prior art flame retardants 
and, therefore, can be used in flexible urethane foams without materially 
affecting the physical properties of such foams. By the term relatively 
low OH numbers, it is meant to designate OH numbers below about 150 and 
preferably below 100. The compounds of the present invention are further 
characterized by the fact that they are substantially linear polymers when 
compared to those disclosed in the prior art. 
The polyalkylene glycol alkyl or haloalkyl polyphosphonates of the present 
invention, when employed in sufficient quantity, will yield a 
self-extinguishing polyurethane foam. This characteristic is particularly 
important in the area of flexible foams due to the wide use of such foams 
in hospitals, homes and automobiles. Normally, the compounds of the 
present invention can be employed in amounts of from about 3 to about 30 
percent, by weight, of the entire foam forming mixture to yield 
self-extinguishing foams. Preferably, they are employed in amounts from 3 
to 10 percent, by weight, of the entire mixture. It is understood, 
however, that this amount will vary depending upon the particular foam 
being used, and that the required proportions can easily be determined 
with a minium amount of blending work. 
While the compounds of the present invention are primarily intended for use 
in urethane foams, it is contemplated that they can also be used in a wide 
variety of polymeric systems. Illustrative of these systems are: 
polyester, polyolefins, cellulose ethers and esters, urethane coatings and 
elastomers, polymethyl methacrylates, polyvinyl chlorides, and many 
others. Furthermore, the compounds of the present invention can also be 
employed in combination with any of the known flame retardants for foams 
or polymeric system such as, for example, tris(dichloropropyl) phosphite, 
tris(chloroethyl) phosphite, tris(dibromopropyl) phosphite, and the like. 
The polyurethane foams within which the flame retardants described above 
are incorporated are well known in the art. They are produced by the 
reaction of a di- or polyisocyanate and a di- or polyhydroxy (polyol) 
compound in the presence of a blowing agent and a catalyst. The foams can 
be made by any of the basic techniques used in foam formation; i.e. the 
prepolymer technique, the semi-prepolymer technique or the one-shot 
process. These techniques are well known and described in the polyurethane 
art. 
As examples of organic di- and polyisocyanates which can be employed to 
make the polyurethane foams there can be employed 
toluene-2,4-diisocyanate; toluene-2,6-diisocyanate; 
4-methoxy-1,3-phenylene diisocyanate; diphenyl methane-4,4'-diisocyanate; 
4-chloro-1,3-phenylene-diisocyanate; 
4-isopropyl-1,3-phenylene-diisocyanate; 
4-ethoxy-1,3-phenylene-diisocyante; 2,4-diisocyanate-diphenylether; 
3,3'-dimethyl-4,4'-diisocyanatodiphenyl methane; mesitylene diisocyanate; 
durylene diisocyanate; 4,4'-methylene-bis (phenylisocyanate); benzidine 
diisocyanate; o-nitrobenzidine diisocyanate; 4,4'-diisocyanatedibenzyl; 
3,3'-bitolylene-4,4'-diisocyanate; 1,5-naphthalene diisocyanate; 
tetramethylene diisocyanate; hexamethylene diisocyanate; decamethylene 
diisocyanate; toluene-2,4,6'-triisocyanate; tritolylmethane triisocyanate; 
2,4,4'-triisocyanatodiphenyl ether; the reaction product of toluene 
diisocyanate with trimethylolpropane; and the reaction product of toluene 
diisocyanate with 1,2,6-hexanetriol. 
Alternatively, as the polyisocyanate there can be used prepolymers made by 
reacting one or more of the above polyisocyanates with a di- or 
polyhydroxy compound such as a polyester having terminal hydroxyl groups, 
a polyhydric alcohol, glycerides or hydroxy containing glycerides, etc. 
These prepolymers should have terminal isocyanate groups and, to insure 
their presence, it is frequently desirable to employ an excess of 5% or 
more of the polyisocyanate in forming the prepolymer. Typical examples of 
such prepolymers having isocyanate and groups are those formed from 
toluene diisocyanate and polyhydroxy compounds. In most cases, a mixture 
of 80% of the 2,4-isomer and 20% of the 2,6-isomer of toluene diisocyanate 
is employed in making these prepolymers. Thus, there can be used the 
prepolymers resulting from the reaction between toluene diisocyanate and 
caster oil, blown tung oil, blown linseed or blown soya oil, and of 
toluene diisocyanate and the polyester of ethylene glycol, propylene 
glycol and adipic acid. 
Examples of suitable polyols are polyethylene glycol, polypropylene 
glycols, ethylene glycol, diethylene glycol, triethylene glycol, propylene 
glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, 
thiodiglycol, glycerol, trimethylolethane, trimethylolpropane, ether 
triols from glycerine and propylene oxide, other containing triols from 
1,2,6-hexanetriol and propylene oxide, sorbitol-propylene oxide adducts, 
pentaerythritol-propylene oxide adducts, trimethylol phenol, oxypropylated 
sucrose, triethanolamine, pentaerythritol, diethanolamine, castor oil, 
blown linseed oil, blown soya oil, N,N,N',N'-tetrakis(2-hydroxyethyl) 
ethylenediamine, N,N,N',N'-tetrakis(2-hydroxypropyl) ethylenediamine, 
N,N,N',N",N"pentakis(2-hydroxypropyl) diethyl triamine, 
N,N,N',N",N"-pentakis(2-hydroxyethyl) diethylene triamine, mixed ethylene 
glycolpropylene glycol adipate resin, polyethylene adipate phthalate and 
polyneopentylene sebacate. 
In preparing the foamed polyurethanes there can be used any of the 
conventional basic catalysts such, for example, as N-methyl morpholine, 
N-ethyl morpholine, 1,2,4-trimethylpiperazine, trimethyl amine, triethyl 
amine, tributyl amine and other trialkyl amines, the esterification 
product of adipic acid and diethylethanolamine, triethyl amine citrate, 
3-morpholinopropionamide, 1,4-bis(2-hydroxypropyl)-2-methylpiperzine, 
2-diethylaminoacetamide, 3-diethylaminopropionamide, diethylethanolamine, 
triethylenediamine, N,N,N',N'-tetrakis (2-hydroxypropyl) ethylenediamine, 
N,N'-dimethylpiperazine, N,N-dimethylhexahydroaniline, tribenzylamine and 
sodium phenolate. Also applicable are tin compounds, e.g. hydrocarbon tin 
alkyl carboxylates such as dibutyltin dilaurate, dibutyltin diacetate, 
dibutyltin dioctoate, tributyltin monolaurate, dimethyltin diacetate, 
dioctyltin diacetate, dilauryltin diacetate, dibutyltin maleate, 
hydrocarbon tin alkoxides, e.g. dibutyltin diethoxide, dibutyltin 
dimethoxide, diethyltin dibutoxide as well as other tin compounds, e.g. 
octylstannoic acid, trimethyltin hydroxide, trimethyltin chloride, 
triphenyltin hydroxide, trimethyltin chloride, triphenyltin hydride, 
triallyltin chloride, trioctyltin fluoride, dibutyltin dibromide, 
bis-(carboethoxymethyl) tin diiodide, tributyltin chloride, trioctyltin 
acetate, butyltin trichloride, octyltin tris(thiobutoxide), dimethyltin 
oxide, dibutyl tin oxide, dioctyltin oxide, diphenyltin oxide, stannous 
octanoate, and stannous oleate. 
Any of the conventional surfactants can be used in amounts of 1% or less, 
e.g. 0.2% by weight of the composition. The preferred sufactants are 
silicones, e.g. polydimethyl siloxane having a viscosity of 3 to 100 
centistokes, triethoxydimethyl polysiloxane, molecular weight 850 
copolymerized with a dimethoxypolyethylene glycol having a molecular 
weight of 750. 
The foaming reaction can be carried out by adding water to the polyol prior 
to or simultaneously with the addition of the polyisocyanate. 
Alternatively, foams can be prepared by the use of a foaming or blowing 
agent. These are usually a liquefied, halogen substituted alkane such, for 
example, as methylene chloride. Especially preferred are those halogen 
substituted alkanes having at least one fluorine atom in their molecules 
such as trichlorofluoromethane, dichlorodifluoromethane, 
dichloromonofluoromethane, chlorodifluoromethane, 
dichlorotetrafluoroethane. In using these blowing agents, they are 
uniformly distributed in either the polyol reactant or the polyisocyante 
reactant whereupon the reactants are mixed permitting the temperature of 
the mixture to rise during the ensuing reaction above the boiling point of 
the liquefied gas so as to produce a porous polyurethane. It should be 
noted that foaming may also be affected by combining the use of a blowing 
agent with the addition of water to the polyol. 
Having generally described the invention, the following examples are given 
for purposes of illustration. It will be understood that the invention is 
not limited to these examples but is susceptible to different 
modifications that will be recognized by one of ordinary skill in the art.

EXAMPLE 1 
To a 30 gallon reactor is charged 50.6 pounds of diethylene glycol, 65.6 
pounds of trimethylphosphite, 123 pounds of O-dichlorobenzene and 48 grams 
of sodium methoxide (25% solution in methanol). The reaction mixture is 
heated (in a nitrogen atmosphere) to about 100.degree. C. and maintained 
at their temperature for about 21/4 hours with removal of volatiles. A 
vacuum is slowly applied to the reactor (to 54 mm Hg) with the temperature 
cooling to 180.degree. F., the volatiles are further stripped in this 
manner for 45 minutes. 
To the resultant product is added 120 grams of methyl iodide and 14 pounds 
of O-dichlorobenzene. The resultant mixture is heated (in a nitrogen 
atmosphere) to reflux and held at about 165.degree. C. for 1/2 hour. The 
reaction temperature is increased to about 180.degree. C. and maintained 
there for an additional 71/2 hours with removal of volatiles. The product 
obtained is a viscous clear colorless liquid with an acid number of 0.54 
milligrams of KOH per gram of sample in water and neutral in CH.sub.3 OH. 
Analysis of the product confirmed the structure to be poly(diethylene 
glycol methylphosphonate), having an average n value of 6.5. 
Analysis: % P = 17.9 OH Number = 62. 
EXAMPLE 2 
To a 0.5 liter 3-necked round bottom flask equipped with a mechanical 
stirrer, thermometer and distillation head is charged 106 grams (1 mole) 
of diethylene glycol, 136.4 grams (1.1 moles) of trimethylphosphite and 
0.25 grams of sodium methoxide (25% in methanol). The reaction mixture is 
vigorously agitated while it is heated to from about 100.degree. to 
110.degree. C. and it is maintained at about 110.degree. C. until about 70 
to 80% of the theoretical quantity of methanol is evolved, i.e. about 2 
hours. The reaction mixture is further stripped of volatiles by gradually 
reducing the pressure inside the flask to about 120 mm Hg by aspirator. 
To the resultant product is added 0.5 grams of methyl iodide in 100 
milliliters of O-dichlorobenzene. The resultant mixture is heated (in air) 
to reflux at 180.degree. C. and maintained at this temperature for 8 
hours. The reaction mixture is cooled to about 100.degree. to 110.degree. 
C. It is essentially neutral, however, ethylene oxide is introduced to 
remove most of the residual acidity. The volatiles are removed from the 
reaction mixture by distillation at 110.degree. C. and 8-15 mm Hg. The 
product is a viscous clear colorless liquid and is obtained in about 
80-90% yield. 
Analysis of the product confirmed the product to be poly(diethylene glycol 
methylphosphonate) having an average n value of 14. 
Analysis: % P = 18.0 (Theory 19.6); Acid No. = 0.3 mg KOH/g sample in 
water; Acid No. = nil in Ch.sub.3 OH; OH No. = 60; Infrared analysis 
revealed OH, P=O and P--CH.sub.3 ; bonds at 3450 cm.sup.-1, 1230 
cm.sup.-1, and 1310 cm .sup.-1, respectively. 
EXAMPLE 3 
A flask fitted with a mechanical stirrer, thermometer, and distillation 
head is charged with 212 grams (2.0 moles) of diethylene glycol, 332 grams 
(2.0 moles) of triethylphosphite, and 0.16 grams Na in 5 milliliters of 
methanol. The reaction mixture is vigorously agitated and heated to from 
about 120.degree. C. to 135.degree. C. over a period of about 3 hours. The 
reaction is further stripped of volatiles under aspirator vacuum at a 
temperature of about 90.degree. to 100.degree. C. 
The remaining product is dissolved in 150 grams of O-dichlorobenzene to 
which 1.3 grams of methyl iodide is added. The mixture is heated (in air) 
to reflux and maintained at a temperature of about 170.degree.-180.degree. 
C. for about 5 hours. The solvents are removed under aspirator pressure at 
a temperature of about 80.degree.-110.degree. C. for about 11/2 hours, 
with removal of volatiles. The product obtained is a viscous clear 
colorless liquid having an acid number in water of 8.12 mg of KOH per gram 
of sample. Analysis of the product confirmed the product to be 
poly(diethylene glycol ethylphosphonate): 
Analysis: % P + 17.1 OH No. + 94. 
EXAMPLE 4 
To a liter flask equipped with a mechanical stirrer, thermometer and 
distillation head is charged 402 grams (3.0 mole) of dipropylene glycol, 
409.2 grams (3.3 mole) of trimethyl phosphite and 0.8 grams of sodium 
methoxide (25% methanol). The reaction mixture is stirred and heated to 
about 110.degree. C. while 166 grams of volatiles are collected. The 
reaction mixture is then further stripped of volatiles under aspirator 
pressure. 
To the remaining product is added 400 grams of O-dichlorobenzene. This 
reaction mixture is cooled to room temperature and 1.0 grams of methyl 
iodide is added. The mixture is heated to 105.degree. C. for 21/2 hours. 
The temperature is raised to 180.degree. C. and the reaction is continued 
for another 4 hours. The remaining volatiles are stripped under aspirator 
pressure. The resultant product has an acid number in water of 1.68 mg of 
KOH per gram of sample. Analysis of the product confirms the product to be 
poly(dipropylene glycol methylphopshonate). 
Analysis. OH No. = 46 % P = 14.9. 
EXAMPLE 5 
This example illustrates the preparation of the intermediate 
poly(diethylene glycol methylphosphite). 
To a 5 liter flask fitted with a mechanical stirrer, thermometer, and 
distillation head is added 1,802.0 grams (17.0 moles) of diethylene glycol 
and 2,318.8 grams (18.7 moles) of trimethyl phosphite. The reaction 
mixture is stirred and heated to a temperature of 110.degree. C. in the 
absence of a transesterification catalyst while collecting volatiles for 
about 41/2 hours. The reaction mixture is further stripped under aspirator 
pressure for about 1/2 hour. The product is collected in 95% yield. 
EXAMPLE 6 
The product made according to the procedure of Example 1 is incorporated 
into a polyurethane foam formulation as set forth in Table I, below. 
TABLE I 
______________________________________ 
Polyol (Voranol CP 3000, made by Dow Chemical Co. 
a 3000 molecular weight propoxylated glycerol) 
700 gms 
Poly(diethylene glycol methylphosphonate) 
prepared according to Example 1 
49 gms 
Water 28 gms 
Silicone surfactant L-548 made by Union Carbide 
7 gms 
N-ethyl morpholine 0.66 gms 
67% dimethylaminoethyl ether in dipropylene glycol 
0.46 gms 
33% 1,4-diazobicyclo [2.2.2] octane in dipropylene 
glycol 0.98 gms 
Stannous octoate, 50% in dioctyl phthalate 
2.8 gms 
Toluene diisocyanate (80/20 isomers) 
370 gms 
FOAM PROPERTIES 
Color White 
Odor None 
Density - 
(lb./ft.sup.3) 
1.47 
Air flow - 
(ft..sup.3 /min.) 
2.1 
Indent Load 
Deflection - 
(ILD, 25% lb.) 
25 
FOAM FLAMMABILITY 
Motor Vehicle Safety Standard 
SE/NBR 
(MVSS 302) Initial (self-extin- 
guishing, no 
burning rate) 
______________________________________ 
EXAMPLE 7 
The product made according to the procedure of Example 4 is incorporated 
into a polyurethane foam formulation as set forth in Table II, below. 
TABLE II 
______________________________________ 
Polyol (Voranol CP 3000) 750 gms 
Poly(dipropylene glycol methylphosphonate) 
according to Example 4 75 gms 
Water 30 gms 
Silicone surfactant L-548 7.5 gms 
N-ethyl morpholine 1.2 gms 
67% dimethylaminoethyl ether in dipropylene glycol 
0.8 gms 
33% 1,4-diazobicyclo [2.2.2] octane in dipropylene 
glycol 1.8 gms 
Stannous octoate, 50% in dioctyl phthalate 
3.0 gms 
Toluene diisocyanate (80/20 isomers) 
418 gms 
FOAM PROPERTIES 
Color (initial) 
Yellow 
Odor Some 
Density - 
(lb./ft..sup.3) 
1.41 
ILD, 25% lb. 
29 
65% lb. 60 
FOAM FLAMMABILITY 
MVSS 302 
Initial SE 
Dry heat 72 hrs/ 
93.degree. C. SE 
______________________________________