| Abstract: | The degradation mechanism of styrene–polyester copolymer was studied by various experimental techniques such as TGA, DTA, IR spectroscopy, pyrolysis gas chromatography, and GCMS (gas chromatography–mass spectrometry). It is concluded that, mainly, there are two first-order degradation reactions during thermal degradation in the presence of air. The first step involves the scission of crosslinks/weak links with liberation of free linear chains. The second degradation step involves random scission of the free linear chains into smaller fragments. The various fragments were identified by pyrolysis gas chromatography and by GCMS. In oxygen atmosphere, the polymer was found to obey first-order kinetics with a single rate constant. Apparently, due to presence of oxygen species at the degrading surface, the two rate constants obtained during thermal degradation reaction are altered in such a fashion as to give a single rate constant. |
