THERMOSTABLE AND FIREPROOF HALOGEN-SUBSTITUTED POLY(DIPHENYLENEPHTHALIDES)

Thermal stability and fire-retarding properties of halide-substituted poly(diphenylenephthalides) were studied depending on the halogen type and concentration. It was found that the concentration dependences of the decomposition onset temperature in an inert medium, thermal stabi lity in air, and oxygen index are described by curves with extrema. It was established that the stabilizing effect of bromine introduced int o the polymer chain exceeds the analogous action of chlorine. The yiel d of coke as a function of the halogen content in a polymer was determ ined and the corresponding correlation equations were derived. It is d emonstrated that bromine- substituted poly(diphenylenephthalides) can be used as additives inhibiting the thermooxidative degradation of pol y(arylenephthalides).