Thermal decomposition kinetics of azomethine oligomer and its some metal complexes

Abstract

In our previous study, we presented the synthesis, characterization, and some physical properties of a new azomethine oligomer and its some metal complexes. This study focuses on the thermal decomposition kinetics of these reported materials. The studied compounds were 1,4-bis[(2-hydroxyphenyl)methylene]phenylenediamine, oligo-1,4-bis[(2-hydroxyphenyl)methylene] phenylenediamine, and oligo-1,4-bis[(2-hydroxyphenyl)methylene]phenylenediamine–metal complexes. Several kinetic methods based on a single heating rate such as Coats-Redfern, MacCallum-Tanner, van Krevelen, Horowitz-Metzger, Wanjun-Yuwen-Hen-Cunxin, and Madhusudanan-Krishnan-Ninan were used to elucidate the kinetic parameters of the decomposition processes. The parameters such as activation energy E, frequency factor A, reaction order n, entropy change ΔS*, enthalpy change ΔH*, and Gibbs free energy change ΔG* were calculated by means of the above methods. The activation energy values obtained by each method were in good agreement with each other. An appropriate mechanism for the thermal decomposition process of each material was also determined by means of the thermogravimetric analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010