Study on isothermal curing kinetics of Bisphenol-AP-based benzoxazine

A novel difunctional benzoxazine monomer was synthesized from the reaction of 4,4'-(1-phenylethylidene) bisphenol(bisphenol-AP) with formaldehyde and n-octylamine.The chemical structures were identified by FT-IR and 1H NMR analyses.The curing kinetics was studied by isothermal differential scanning calorimetry(DSC).The results revealed that the curing reaction of the bisphenol-AP-based benzoxazine was chemical kinetics control at the early stage,and the effect of the diffusion controll was much evident in later reaction stage.It was of autocatalyzed and diffusion controlled characteristics,there was some deviations between experimental data and autocatalytical data in the later stage.Diffusion factor was incorporated to empirical equation in order to predict the curing kinetic.The modified autocatalytic model showed good agreement with experimental results.