Thermal degradation of glass reinforced epoxy resin and polychloroprene rubber: the correlation of kinetic parameters of isothermal accelerated aging with those obtained from non-isothermal data

The results of a kinetic investigation of the non-isothermal and isothermal degradation of a mechanical property for glass reinforced epoxy resin (GRER) and polychloroprene rubber (PCL-R) are presented. For each of the materials investigated, similar dependences of the activation energy on the degree of conversion were obtained from non-isothermal data and from the thermal accelerated aging of the mechanical property (flexural strength, for GRER; residual deformation under constant deflection, for PCL-R). The obtained results are arguments for the quasichemical approximation according to which the degradation of a mechanical property of a polymeric material is due to a chemical reaction that can be described by equations from chemical kinetics. In the particular case of GRER, in which E is constant in the range 0.05 less than or equal to alpha less than or equal to 0.40, the value of the activation energy obtained from non-isothermal data can be used for rapid prediction of the thermal lifetime. (C) 2001 Elsevier Science Ltd. All rights reserved.