A KINETIC-ANALYSIS OF THE CURING REACTION OF AN EPOXY-RESIN

The kinetics of a curing reaction under non-isothermal conditions using DSC is discussed. A simple, consistent method of kinetic analysis was applied. The method allows the correct determination of the most suitable kinetic model and the calculation of kinetic parameters. This method was used to study the kinetics of an epoxy resin based on diglycidyl ether of bisphenol A, cured by methyl tetrahydrophthalic anhydride with an accelerator. An activation energy of 73 kJ mol-1 was calculated and the autocatalytic kinetic model (Sestak-Berggren equation) was found to be the most covenient description of the studied curing process. The isothermal curves calculated for the kinetic parameters determined in non-isothermal conditions are in good agreement with experimental curves when the curing temperature T(c) is above the maximum glass-transition temperature of the system, T(g infinity) = 109-degrees-C. The influence of the vitrification phenomenon is discussed when T(c) is below T(g infinity). The temperature-time-transformation diagram of the studied epoxy system has been constructed and is discussed.