Thermal Degradation of Phosphorus Esters of 1,4-Butanediol and 2-Butyn-l,4-diol

摘要

Compounds containing alkyne unsaturation or propensity to form such unsaturation when heated are thought to be superior flame-retarding agents because of their tendency to undergo cycloaddition processes leading to char formation. To test this assumption, a series of phosphorus esters of 2-butyn-l,4-diol has been prepared and characterized. The thermal degradation of these compounds has been compared to that of the corresponding saturated analogs derived from 1,4-butanediol. The prominet degradation pathway for the saturated esters would appear to be elimination of a phosphorus acid while that for the alkyne esters would appear to be heterolytic cleavage of carbon-oxygen bonds to form propargylic cations which leads to rapid char formation.