THERMAL-DEGRADATION OF BLENDS OF POLYSTYRENE AND POLY-4-METHOXYSTYRENE WITH BISPHENOL-A POLYCARBONATE

Blends of polystyrene (PS) and poly-4-methoxystyrene (PMeS) with bisph enol A polycarbonate (PC) (1:1 by weight) have been studied using ther mogravimetry (TG) and thermal volatilisation analysis (TVA). The conde nsable volatile products obtained in the TVA experiments were separate d by subambient TVA and the less-volatile liquids were examined by GC- MS. The cold ring fraction of products was characterised by IR spectro scopy. On degradation, both PS-PC and PMeS-PC blends show an interacti on which is observed as a destabilisation. It is suggested that in the degrading blends, the PC component is destabilised as a result of tra nsport of small radical species from the other polymer phase. These ra dicals may abstract hydrogen atoms, leading to an increase in backbone scission reactions and consequently a lower degradation temperature t han when the polymer is degraded alone.