Thermal decomposition of 2,4,4,5,5-pentaphenyl-1,3,2-dioxaphospholane

摘要

Certain five-membered dioxaheterocyclic compounds (hetero atoms may be P, Si, S, etc.) contain a strained carbon-carbon bond which may undergo homolytic thermolysis at modest temperatures to generate a diradical capable of initiating vinyl polymerization. If substituents contain flame-retarding moieties this represents a convenient method for imparting flame retrdancy to a polymeric material. Of particular interest has been 2,4,4,5,5-pentaphenyl-1,3,2- dioxaphospholane. The thermal degradation of this compound has been studied using ~(13)C NMR spectroscopy. This may conveniently be done by monitoring the intensity of the signal for the benzylic carbon atom as a function of time and temperature. A simple transformation is the conversion of the cyclic compound to the linear polymer.