Thermal degradation kinetics of poly {N-[(4-bromo- 3,5-difluorine)-phenyl]maleimide-co-styrene} in nitrogen

Abstract

The nonisothermal degradation kinetics of the copolymer poly{N-[(4-bromo-3,5-difluorine)phenyl]maleimide-co-styrene}, which was synthesized with N-[(4-bromo-3,5-difluorine)phenyl]maleimide and styrene, were studied by thermogravimetry/derivative thermogravimetry techniques. The kinetic parameters, including the activation energy and the pre-exponential factor of the copolymer degradation process, were calculated by the Kissinger and Flynn-Wall-Ozawa methods. The thermal degradation mechanism of the copolymer was also studied with the Satava-Sestak method. The results show that the activation energies were 165.97 kJ/mol with the Kissinger method and 169.04 kJ/mol with the Flynn-Wall-Ozawa method. The degradation of the copolymer followed a kinetic model of a nucleation and growth and the kinetic equation could be expressed as G(α) = [-ln(1- α)]1/2 [where G(α) is the integral function of conversion and α is the extent of conversion of the reactant decomposed at time t]. The reaction order was 1/2.