Cure reactions in the blend of dicyclopentandiene bisphenol cyanate ester with epoxy resin

The cure reactions of dicyclopentandiene bisphenol cyanate ester (DCPDCE) associated with an epoxy resin (2,2—bis (4—glycidyloxy phenyl) propane) were investigated using gel test, FTIR and DSC dynamic scanning at different stoichiometric ratios. It was observed that the epoxy resin not only catalyzed the trimerization of the cyanate ester which decreased the gel time of the EP/DCPDCE blends, but also diluted the cyanate ester which increased the gel time of the blends. When the weight fraction of EP in the EP/DCPDCE blend was 25wt%, the two effects of EP were balanced and the gel time of the blend was almost the same as that of the pure DCPDCE. When the blends were cured following the curing cycle, the reaction of producing triazine rings and oxazoline took place at the low temperature (160~180℃) step of the curing cycle, and the reaction of epoxy functions with the triazine rings former in the initial step as well as the isomerization of oxazoline to oxazolidinone took place at the high temperature (200~220℃) step. The structure of the final cured resin was related to the initial epoxy resin concentration of the blends.