Claims
- 1. A process for producing a phosphazene polymer foam which comprises:
- (a) thermally polymerizing a cyclic compound of the formula (NPCl.sub.2).sub.y wherein y is 3, 4, or mixtures thereof with a catalytically sufficient amount of a compound having the formula M(OR').sub.x, wherein M is an alkali metal or an alkaline earth metal, x is equal to the valence of the metal M, and R' is C.sub.1 to C.sub.10 linear or branched alkyl, C.sub.1 to C.sub.10 substituted linear or branched alkyl, the substituent selected from the group consisting of nitro, C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl and C.sub.6 to C.sub.10 aryloxy radicals to form a phosphazene polymer;
- (b) contacting the resulting phosphazene polymer with a metal compound having the formula
- M(OC.sub.6 H.sub.4 R.sub.1).sub.x,
- M(OC.sub.6 H.sub.4 R.sub.2).sub.x, or mixtures thereof
- wherein M is an alkali metal or alkaline earth metal, x is equal to the valence of said metal M, and R.sub.1 and R.sub.2 are the same or different and are selected from the group consisting of C.sub.1 to C.sub.10 alkyl radical, C.sub.6 to C.sub.10 aryl radical, C.sub.1 to C.sub.10 substituted C.sub.1 to C.sub.10 alkyl radical and substituted C.sub.6 to C.sub.10 aryl radical, the substituent selected from the group consisting of halogen, nitro, cyano, C.sub.1 to C.sub.4 alkyl, C.sub.1 to C.sub.4 alkoxy, C.sub.6 to C.sub.10 aryl and C.sub.6 to C.sub.10 aryloxy radicals, thereby forming a phosphazene polymer which is substantially free of halogen; and
- (c) mixing the resulting phosphazene polymer which is substantially free of halogen with a chemical blowing agent and heating the resulting mixture to a temperature sufficient to decompose said blowing agent and form a foam.
- 2. The process in accordance with claim 1 wherein said blowing agent is 1,1'-bisazoformamide.
- 3. The process in accordance with claim 1 wherein said phosphazene polymer, substantially free of halogen is mixed with a chemical blowing agent and a mixture of curing agents, at least one of said curing agents having an initiation temperature below the temperature at which said chemical blowing agent decomposes; heating the foamable mass to a temperature below the decomposition temperature of said blowing agent, but above the initiation temperature of at least one of said curing agents, for a sufficient time to partially precure the copolymers; and heating the partially precured mass to a temperature above the decomposition temperature of said blowing agent to foam the copolymers and to effect a further cure thereof.
- 4. The process of claim 3, wherein the partial precure is accomplished by heating the foamable mass for about 6 to about 30 minutes at a temperature of from about 200.degree. F. to about 250.degree. F., and the foaming and further curing is accomplished by heating the partially precured mass for about 30 to about 60 minutes at a temperature of from about 300.degree. F. to about 350.degree. F.
- 5. A process for producing a phosphazene polymer foam which comprises:
- (a) thermally polymerizing a cyclic compound of the formula (NPCl.sub.2).sub.y where y is 3, 4, or mixtures thereof with a catalytically sufficient amount of a compound having the formula N.sub.3 P.sub.3 Cl.sub.z (OR').sub.6-z wherein R' is C.sub.1 to C.sub.10 linear or branched alkyl, C.sub.1 to C.sub.10 substituted linear or branched alkyl, the substituent selected from the group consisting of halogen, nitro, C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl and C.sub.6 to C.sub.10 aryloxy radicals and z equals 0 to 5.
- (b) contacting the resulting phosphazene polymer with a metal compound having the formula
- M(OC.sub.6 H.sub.4 R.sub.1).sub.x,
- M(OC.sub.6 H.sub.4 R.sub.2).sub.x, or mixtures thereof
- wherein M is an alkali metal or an alkaline earth metal, x is equal to the valence of said metal M, and R.sub.1 and R.sub.2 are the same or different and are selected from the group consisting of C.sub.1 to C.sub.10 alkyl radical, C.sub.6 to C.sub.10 aryl radical, substituted C.sub.1 to C.sub.10 alkyl radical and substituted C.sub.6 to C.sub.10 aryl radical, the substituent selected from the group consisting of halogen, nitro, cyano, C.sub.1 to C.sub.4 alkyl, C.sub.1 to C.sub.4 alkoxy, C.sub.6 to C.sub.10 aryl and C.sub.6 to C.sub.10 aryloxy radicals, thereby forming a phosphazene polymer substantially free of halogen; and
- (c) mixing the resulting phosphazene polymer which is substantially free of halogen with a chemical blowing agent and heating the resulting mixture to a temperature sufficient to decompose said blowing agent and form a foam.
- 6. The process in accordance with claim 5 wherein said blowing agent is 1,1'-azobisformamide.
- 7. The process in accordance with claim 5 wherein said phosphazene polymer, substantially free of halogen is mixed with a chemical blowing agent and a mixture of curing agents, at least one of said curing agents having an initiation temperature below the temperature at which said chemical blowing agent decomposes; heating the foamable mass to a temperature below the decomposition temperature of said blowing agent, but above the initiation temperature of at least one of said curing agents, for a sufficient time to partially precure the copolymers; and heating the partially precured mass to a temperature above the decomposition temperature of said blowing agent to foam the copolymers and to effect a further cure thereof.
- 8. The process of claim 6 wherein the partial precure is accomplished by heating the foamable mass for about 6 to about 30 minutes at a temperature of from about 200.degree. F. to about 250.degree. F., and the foaming and further curing is accomplished by heating the partially precured mass for about 30 to about 60 minutes at a temperature of from about 300.degree. F. to about 350.degree. F.
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 731,745, filed Oct. 12, 1976.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3370020 |
Allcock et al. |
Feb 1968 |
|
3917802 |
Allcock et al. |
Nov 1975 |
|
4076658 |
Dieck et al. |
Feb 1978 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
731745 |
Oct 1976 |
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