Application of direct nonlinear regression from single TG curve to compounds undergoing simple and complex thermal decompositions

Abstract

Nonlinear regression of the basic kinetic equation was used to determine kinetic parameters of simple and complex decomposition processes related to some pesticides and pharmaceutical substances. The method for this calculation was carried out using a single TG curve.These values were compared with those obtained with model-fitting and model-free methods.Nonlinear regression method is able to define a single mechanism for compounds undergoing one or few steps of decomposition processes. For compounds that undergo many steps of decomposition processes, only the mechanisms of some of them can be hypothesized. C 2003

Pitch pyrolysis kinetics from single TG curve

“…If the model of simple ''global'' kinetics is accepted, determination of kinetic parameters from single TG curve can lead to similar results as isoconversional ''many curves'' methods [3]. Although the physical meaning of kinetic parameters determined from single thermogravimetric experiment is not quite clear, their determination is quick and simple.…”

Thermal degradation of pesticides under oxidative conditions

“…Thermal degradation of some pesticides has already been addressed in past literature [16][17][18][19][20][21][22][23][24][25][26] in particular that of aldoximes [17][18][19][20] and chlorine pesticides [21]. The latter indeed received special attention because of the possibility of formation of very toxic chlorine containing species in case of chemical fires.…”