Investigation of thermal degradation of poly-(4-n-alkylstyrenes) with longalkyl chain (C-6-C-10) by pyrolysis-gas chromatography/mass spectrometry

The thermal degradation of a series of poly(4-n-alkylstyrenes), from hexyl to decyl, has been studied in isothermal conditions at 600 degrees C using pyrolysis-gas chromatography/mass spectrometry. The type and composition of the pyrolysis products gave useful indications about the mechanism of ther mal degradation. It was shown that the main thermal degradation process is depolymerization, like polystyrene. Other thermal reactions involve fragmen tation of alkyl side chains. In particular, a new initiation process for de polymerization of polystyrene based polymers was found: a thermal electrocy clic reaction with the formation of divinylbenzene and alkane. and main cha in scission with formation of two macroradicals. The formation of cyclic or polyaromatic structures does not take place. (C) 2000 Elsevier Science Ltd . All rights reserved.