KINETIC-MODELS FOR THE THERMAL-DECOMPOSITION OF PVC PLASTISOLS

In previous work the effect of the plasticizer and resin on the therma l decomposition of plastisols was studied. The derivative curves of th e thermograms showed complex behaviour as a consequence of the interac tions between the plasticizer and the resin prior to the decomposition . In this work, two groups of kinetic models are proposed in order to explain this complex behaviour. Both groups consider that the plastici zer volatilises from the sample following a single reaction. The M1P16 model considers that the PVC decomposition takes place via two sets o f parallel/consecutive reactions with an intermediate species that und ergoes further decomposition. The M2P17 model considers that the inter actions between the plasticizer and the resin leads two differentiated fractions in the PVC with different levels of plasticisation, both de composing at well differentiated temperatures. From M1P16 and M2P17, d ifferent models have been derived and the corresponding parameters hav e been obtained. A discussion is presented regarding the interpretatio n of the kinetic parameters obtained by the different models. (C) 1996 Elsevier Science Limited