摘要 |
A composition consisting essentially of a polyphosphazene binder having the following repeating units: <IMAGE> wherein n is from about 20 to about 50,000, A is selected from -O- and -NH-, and R1 and R2 are independently selected from alkyl having from one to about 20 carbon atoms, aryl having from 6 to about 14 carbon atoms, alkaryl having from 7 to about 30 carbon atoms, any of the preceding moieties substituted with halogen, hydroxyl, alkoxy, aryloxy, or nitro groups, or any of the preceding moieties linked by ether or amine linkages. Combined with an organic fiber filler, this material provides an erosion resistant insulation composition for temporarily protecting the interior of a rocket motor combustion chamber from thermal damage while the rocket is firing. Provided as a barrier coating or layer between the propellant grain and other structures within a rocket motor, this material prevents migration of plasticizers, nitrate esters, and other fluid or mobile ingredients from the propellant grain.
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