Is the science of thermal analysis kinetics based on solid foundations?: A literature appraisal

A critical appraisal is made of the recent literature concerned with the kinetics and the mechanisms of thermal reactions, particularly research using the methods of thermal analysis (TA). It is concluded that many features of the theories and the practices in customary use are inadequate and/or unsatisfactory. The reaction models that are currently employed lack the necessary coherence required to introduce systematic and scientific order into the extensive information available. There are few reliable, general concepts and chemical principles which are capable of coordinating and classifying the experimental observations and which can contribute to the organic growth of an ordered discipline. Many, though not all, recent published TA studies appear as individual articles that remain largely unrelated to comparable investigations or to the general theoretical principles that are applicable throughout chemistry. This unacceptable situation is identified as having arisen during the emergence and establishment of thermoanalytical science as a distinct discipline, which effectively replaced the former interest in the thermal decompositions of solids, while also retaining concepts from this precursor topic. Overall this transformation was uncoordinated and perhaps has remained largely unrecognized. A consequence was that only some selected aspects of the heterogeneous and homogeneous kinetic theory and reaction models were incorporated into the developing (burgeoning) thermoanalytical subject area. However, during the initial rapid expansion of TA experimental methods, about three decades ago, shortcomings in the theories of thermal decomposition of solids were already becoming apparent, inhibiting advances. Consequently, some earlier optimistic hopes for progress in advancing solid state thermal chemistry were not fully realized. During the redirection of interest from thermal reactions of solids towards thermal methods, TA development proceeded without the appearance of new chemical principles or novel reaction models for general application. Progress in instrumentation predominantly focussed attention towards developing and applying automated calculation methods. This was essential to permit the analyses of larger number of accurate measurements that could be obtained, retained and processed by the more powerful computers that were becoming available to control experiments and to present processed results. The collection and collation of data was achieved m