The Accuracy of Approximation Equations in the Study of Thermal Decomposition Behaviour of Some Synthesized Optically Active PolyamidesThe Accuracy of Approximation Equations in the Study of Thermal Decomposition Behaviour of Some Synthesized Optically

This paper reports on the accuracy of the integral methods used for the kinetic analysis of degradation of synthesized optically active polyamides. For this purpose, thermogravimetric analysis is a technique, widely used in polymer science because of its simplicity. On analyzing data by integral methods, it is necessary to calculate the temperature integral, which does not have an analytical solution. Instead of performing the numerical integration, most of the researchers prefer to avoid the problem by using approximate expressions, not always adequate and several hundreds of citations to the original papers can be found in recent polymer science publications. The most important application of these equations is the determination of the kinetic parameters, in particular activation energies, and not the computation of the Arrhenius integral. A methodical analysis of the errors involved in the determination of the activation energy from these integral methods is invisibly missing. A comparative study on the precision of the activation energy as a function of u and T computed from different integral methods has been carried out. Furthermore, for a series of optically active polyamides, the interpretation of kinetic parameters (E, deltaS, deltaG and deltaH) of thermal decomposition stages has been evaluated and reported.