Laser Mass Spectrometry Analysis of the Formation of Phosphazene-Containing Epoxy Oligomers

The main features of two methods for the synthesis of phosphazene-containing epoxy oligomers— namely, the methods based on oxidation of double bonds in organooxyphosphazenes and on the reaction of chlorocyclophosphazenes with diphenols and the subsequent interaction of the resulting hydroxy-aryloxy phosphazenes with epichlorohydrin—were examined. Using the example of hexa- and octa-eugenol derivatives of the corresponding cyclophosphazenes, optimal conditions were established for the oxidation of allyl groups of these compounds with peroxy acids and hexa- and octa-epoxide cyclophosphazenes were characterized. It was noted that the epoxidation of eugenol derivatives of a mixture of cyclophosphazenes with three to eight phosphazo groups is accompanied by side reactions leading to the formation of P–OH bonds and the partial opening of oxirane cycles. Bisphenol A phosphazene-containing oligoepoxides were synthesized both via the stage involving the formation of hydroxy-aryloxy cyclophosphazenes and their subsequent epoxidation with epichlorohydrin and via the direct interaction of chlorocyclophosphazenes with an excess of bisphenol A (BPA) in the presence of solid alkali. In the latter case, the resulting oligomers are mixtures of the conventional epoxide and phosphazene-containing epoxy oligomers. The content of the latter can be adjusted up to 50%. The synthesized oligomers contain 1–5% phosphorus. They can be cured by conventional hardeners to form flameproof or noncombustible compositions.