TABLE OF CONTENTS Generally, the thermal degradation of a polymeric material follows more than one mechanism. The existence of more than one concurrent chemical reaction accompanied by other physical phenomena such as evaporation and ablation introduce further complications for the modelling of degradation kinetics. The development of workable models able to describe the degradation kinetics of polymers has been the concern of many authors [a.1, a.2] {886353}. Kinetic study of thermal degradation provides useful information for the optimisation of the successive treatment of polymer materials in order to avoid or at least limit thermal degradation [a.3]. The analysis of the degradation process becomes more and more important due to an increase in the range of temperatures for engineering applications, recycling of post-consumer plastic waste, as well as the use of polymers as biological implants and matrices for drug delivery, where depolymerisation is an inevitable process affecting the lifetime of an article. Additionally, scission of macromolecules driven by thermal fluctuations at elevated temperatures provides a good example for the analysis of population dynamics in complex systems. This subject has therefore attracted substantial attention recently.
A valuable approach for measuring thermal degradation kinetic parameters is controlled-transformation-rate thermal analysis (CRTA) a stepwise isothermal analysis and quasi-isothermal and quasi-isobaric method. In this method, some parameters follow a predetermined programme as functions of time, this being achieved by adjusting the sample temperature. This technique maintains a constant reaction rate, and controls the pressure of the evolved species in the reaction environment. CRTA is,...
