The thermooxidative degradation of poly(vinyl chloride). Part I. The stabilising action of dibutyltin maleate and trisnitro (1,3-dihydroxyl-2-hydroxymethyl-2-nitropropane) on PVC in air

Abstract

The thermooxidative degradation and stabilisation of poly(vinyl chloride) (PVC) have been studied using dibutyltin maleate (DBTM) alone and in admixture with varying amounts of trisnitro (1,3-dihydroxy-2-hydroxymethyl-2-nitropropane) compounds as stabilisers. Films of the unstabilised and stabilised PVC were exposed to oven ageing at 100 °C. The degradation reactions were monitored by infrared spectroscopy, colour and gel formation, and determination of time to embrittlement. The results indicate that the stabilising agents containing 7.2 × 10 −3 mol% DBTM in admixture with 5 × 10 −4 mol% of the stearyl ester of the trisnitro compounds are most effective. The relevant mechanisms of stabilisation are discussed.