Poly(Alkyl/Arylphosphazene) Chains and Rings Via Condensation Reactions of Si-N-P Precursors.

摘要

Polyphosphazenes, (R2PN)(n), which can be prepared with a wide variety of substituents at phosphorus, often exhibit useful properties including low temperature flexibility, resistance to chemical attack, flame retardancy, stability to UV radiation, and reasonably high thermal stability. Compounds containing biologically, catalytically, or electrically active side groups are being investigated as are some novel polyphosphazene-graft-polystyrene copolymers. The thermal decomposition of P-functional N-silylphosphoranimines, Me3SiN=P(X)R2, is an effective synthetic route to cyclic and polymeric phosphazenes that are fully substituted with P-alkyl/aryl side groups. Results of some recent studies of this condensation reaction and its products are reported, including: (1) the synthesis of a variety of new precursors with P-alkoxy and P-aryloxy substituents, (2) the effect of the leaving group (X) on the polymerization/cyclization process, and (3) the synthesis of a series of dialkyl cyclic phosphazenes, (R2PN)(n) (e.g., n = 3,4,5; R = Et, n-Pr, n-Bu, n-Hx). Reprints. (AW)