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Scientists have been interested in the reaction kinetics of solids since the early 20th century [1, 2]. In those days the basic experimental techniques known today as differential thermal analysis (DTA), thermogravimetry (TG), and evolved gas analysis (EGA) were developed [1, 3-5]. Initially the kinetic studies were performed under isothermal conditions [1], while the results of non-isothermal methods were started to be used for kinetic evaluations only during the 1922s [5-11]. The first step towards nonisothermal kinetic analysis was taken by Flynn[12]. A practical problem in the interpretation of experimentally determined values of E and A does exist, and it lies in the very nature of the experiments. Standard experimental techniques (e.g., TG, DSC, DTA) as well as more sophisticated methods [10, 11] generally do not allow the isolation of elementary reactions. Rather, they provide a global measure of the rate or extent of a process that usually involves several steps with different activation energies. For this reason, experimentally derived Arrhenius parameters of a solid state process must be interpreted as effective values unless mechanistic conclusions can be justified by ancillary data. Flynn [13] gave an overview of alternat ive expressions to describe the temperature dependence of the reaction rate, none of which has been extensively used. The explosive development of non-isothermal kinetics began in the late 1950s when thermal analysis instruments became commercially available. Since that time there has been an ever increasing number of works dealing with methods of determining Arrhenius parameters and the reaction model from non-isothermal experiments [14]. The initial enthusiasm was due to the practical advantages of the nonisothermal experiments. Firstly, non-isothermal heating resolved a major problem of the isothermal experiment, which is that a sample requires some time to reach the experimental temperature. During the non-isothermal period of an isothermal experiment, the sample undergoes some transformations that are likely to affect the results of the following kinetic analysis. This problem especially restricts the use of high temperatures in isothermal experiments. Secondly, because a single nonisothermal experiment contains information on the temperature dependence of the reaction rate, it was widely believed [14-22] that such an experiment would be sufficient to derive Arrhenius parameters and the reaction model of a process. The advantages of the non-isothermal experimental technique are at least partially offset by serious computational difficulties associated with the kinetic analysis. The kinetic methods can be conventionally divided into differential and integral methods. Differential methods [14-19] use various rearrangements of the basic kinetic equation. These methods can be conveniently applied to the data of DTA and DSC experiments ; they can also be used with TG data if they are preprocessed by differentiation with respect to time or temperature. Unfortunately, numerical differentiation is usually undesirable because it produces very noisy data. To handle TG data, one should use integral methods [16-18, 23, 24] that originate from the various ways of integrating the basic kinetic equation. According to the isoconversional principle, the reaction rate at a constant extent of conversion is only a function of temperature. Kujirai and Akahira [28] were the first to propose an empirical isoconversional equation to evaluate the temperature sensitivity of materials decomposed under isothermal conditions. In non-isothermal kinetics, several isoconversional methods were suggested in the1960s [18-21]. To use these methods, a series of experiments has to be conducted at different heating rates. To avoid inaccuracies associated with analyt ical approximations of the temperature integral, Vyazovkin [26, 27] proposed a nonlinear isoconversional method. According to this method, for a set of n experiments carried out at different heating rates, the activation energy can be determined at any particular value of a by finding the value of Ea for which the kinetic functionis a minimum.

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