On the thermal degradation of poly(styrene sulfone)s VIII. Effect of structure on thermal characteristics

Poly(olefin sulfone)s obtained by the free radical copolymerization of different olefins, vinyl chloride, acrylamide, and styrene, with sulfur dioxide, denoted PVCS, PAaS and PStS, have been investigated by thermogravimetric analysis (TGA). The activation energy, pre-exponential factor, and decomposition order of thermal degradation of these poly(olefin sulfone)s with similar SO2 mole fractions were obtained from TGA measurements in nitrogen. Comparison of the values of activation energy at the early stage, shows that the thermal stability decreases in the order: PStS>PVCS>PAaS; this can be explained by the electronegative effect of the substituent in the side chain of the olefin. Moreover, in the later stage, the thermal stability decreases in the order: PStS<PVCS<PAaS; this phenomena can be explained by the effect of the polyolefin structure on the thermal stability. (C) 2002 Elsevier Science Ltd. All rights reserved.