Thermal degradation of poly(diethyl vinylphosphonate) and its copolymer

Abstract

Thermal degradation of poly(diethyl vinylphosphonate) and diethyl vinylphosphonate/vinyl alcohol copolymer was investigated using thermogravimetry, infra-red spectroscopy and g.c.-mass spectrometry. For poly(diethyl vinylphosphonate), little chain scission occurred and the high stability may be attributed to POP crosslinkages between phsophonate units. With the diethyl vinylphosphonate/vinyl alcohol copolymer, the presence of hydroxyl groups in the polymer chains inhibited the formation of the POP crosslinkages. The main degradation products from the copolymer were aldehydes having the general formula HC(O)(CHCH) nCH 3 and methyl ketones having the formula H 3CC(O)(CHCH) nCH 3 and CH 3C(O)(CHCH) nCHCH 2, where n = 1, 2, 3. The introduction of phosphonate unit into poly(vinyl alcohol) is less effective than that of phosphate unit in enhancement of thermal stability.