Radiation Induced Polymerization of Cyclophosphazene Trimers

摘要

Hexachlorophosphazene was irradiated in bulk and in solution after various methods of purification. When rigorously dried and purified good yields of polymer were obtained. Poor reproducibility was found in the bulk but reasonably good results were obtained in decalin solution. The best yields and highest molecular weights were obtained after the addition of small amounts of the bulky electron acceptor pyromellitic dianhydride. Hexachlorocyclotriphosphazene was purified by recrystallization for various times from dried heptane. The trimer was then further purified by repeated sublimation steps under high vacuum. Finally the trimer was dried in the melt over rigorously baked out barium oxide. The monomer was then transferred to ampules or the NMR tubes for radiation and subsequent determination of the polymer content. (AW)