Сравнительный кинетический анализ термической деструкции гидрогеля на основе полиметилвинилового эфира малеиновой кислоты сшитого полипропиленгликолем

Abstract

Kinetic analysis was made applying TG/DTG/HF data in nitrogen and air atmospherefor thermal decomposition of hydrogel of polymethylvinyl maleic acid ester, linked with polypropylene glycol, at different heating rates. TG/DTG/HF data were processed according to the followingkinetic models: Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Coates-Redfern and nonparametric kinetic method (NPK) was used, to obtain the following kinetic parameters: activationenergy and pre-exponential factor.According to the attained values of activation energy, the mechanism of degradation of the hydrogel was suggested. Values of kinetic parameters attained by different methods, are compliant to eachother. Isoconversion method is one of the methods for definition of activation energy; this methoddoes not require knowledge on analytical form of conversion function, and gives the possibility todefine the activation energy against conversion degree as well.To obtain full kinetic analysis it is necessary to process the data using non-parametric kineticmethod. Non-parametric kinetics method (NPK) of Serra, Nomen and Sempere is based upon thesuggestion that reaction velocity may be expressed as multiplication of two independent functions,f (α) and k (T). Reaction model f (α) considers the dependence of conversion degree, and k (T)considers the temperature dependence.