SYNTHESIS OF HYDROLYTICALLY STABLE PHOSPHORUS-CONTAINING POLYMERS VIAPOLYCONDENSATION AND THEIR UTILIZATION IN POLYMER BLENDS

Amorphous polyarylene ether home-and copolymers were synthesized which were based upon bisphenol A and either 4,4'-dichlorodiphenylsulfone, 4,4'difluorobenzophenone or 4,4'-difluorodiphenyl phenylphosphine oxid e. Solution blends were prepared from these home-and copolymers with l inear bisphenol A based polyhydroxyether, which was used as a model fo r the epoxy or vinyl ester thermosetting matrix resins for composite m aterials. It was observed that transparent, single Tg blends could be prepared from the phosphine oxide containing homopolymer and a 50/50 p hosphine oxide/dichlorodiphenylsulfone copolymer. The other homopolyme rs produced materials with two Tg's, implying that they were definitel y phase separated systems. Thermogravimetric analysis was also conduct ed and the phosphine oxide blends produced high char yields suggesting utilization in fire-resistant applications. The miscibility of the ph osphine oxide material has been attributed to specific hydrogen bondin g interactions observed between the phosphine oxide bond and the secon dary hydroxyl group in the polyhydroxy ether. This hydroxyl functional ity is also present in the epoxy and vinylester precursors and it is s uggested that these materials could be utilized as interface sizings f or carbon fibers, which would produce a graded microstructure between the fiber and the polymer matrix systems.