Curing kinetics study of benzoxazine using diaryliodonium salts as thermal initiators

In this study, the effects of three different diaryliodonium salts-diaryliodonium tetrafluoroborate (DT), diphenyliodonium hexafluorophosphate (PF) and diphenyliodonium hexafluoroarsenate (AS)-as catalysts on the thermal curing of bisphenol A‐based benzoxazine (BA) were examined. Resin systems consisting of BA and diaryliodonium salts (BA/ArIx) were prepared. The thermal curing behavior and mechanisms of BA/ArIx were investigated by differential scanning calorimetry (DSC) and in-situ Fourier transform infrared (in-situ FTIR) spectroscopy. The thermal curing kinetics and kinetic model of BA/ArIx systems were investigated by non-isothermal DSC. Based on the results obtained from in-situ FTIR, ArIx underwent a two-stage reaction for accelerating the curing of BA. Kinetic data indicate that the BA/ArIx system exhibits activation energy slightly greater than that of BA. Both BA and BA/ArIx followed an autocatalytic kinetic model based on the Friedman method, and the theoretically calculated curves exhibited good agreement with experiment data.