Kinetic analysis of the curing of branched phthalonitrile resin based on dynamic differential scanning calorimetry

The aim of this work was to systematically investigate the kinetics of the curing reaction of branched phthalonitrile resin containing both flexible moiety and rigid aromatic structure in backbones with 4, 4′-diaminodiphenyl sulfone (DDS) as hardener. Differential scanning calorimetric (DSC) was mainly utilized with non-isothermal mode at different heating rates. The activation energy and the dependence of the curing activation energy with conversion were calculated and discussed based on Starink methods. Results showed that the curing reaction between branched phthalonitrile resin and 5 wt% DDS was chemistry and diffusion controlled. The predicted curves of autocatalytic kinetic model fit well with the non-isothermal DSC data that was important for predicting curing behavior of other complex phthalonitrile system.