Structure and property of co-curing reaction product for epoxy and cyanate resin system

The influence of the behavior, mechanism, product structure and relation of structure with properties for co-curing reaction of epoxy resin and cyanate ester system catalyzed by transition metal acetylaceton, etc. was studied. The results show that the accelerator can obviously accelerate the co-curing reaction of the resin system and decrease the cured temperature and curing time. The reactions involved in the co-curing are: cyclodimerization and cyclotrimerization of cyanate, polyether-fication of epoxy group and cyclotrimerization of cyclic dimmer, as well as the formation of oxazolidone rings. In the lack of cyanate functional groups, the main structures of cured compounds are oxazolidone and polyether structure in the cured resin, and the triazine ring structure is of minor importance. In the excess of cyanate functional groups, the main structures are triazine ring and oxazolidone structure in the cured resin, and the polyether structure is of minor importance. The reactive activation energy and frequency factor of the co-curing resin system increase with enhanced concentration of cyanate. The thermal stability and dielectric properties of the cyanate and epoxy resin curing system are also found to increase with enhanced concentrations of cyanate in the same cured condition.