热熔型 BA221 氰酸酯树脂的固化动力学及流变行为

Cyanate ester (CE) resin has highly symmetrical chemical structure and strong crystallinity, high curing reaction temperature, and high brittleness of cured products. It is easy to crystallize and separate from prepreg and suspend on the surface, seriously affecting the apparent quality, preparation process, and mechanical properties of prepreg. In this paper, F-51 phenolic epoxy modified CE resin was used to prepare a hot melt CE resin (code: BA221). It has the characteristics of good film formation, long shelf life, and is suitable for hot melt prepreg process. The curing kinetics and curing reaction parameters of BA221 resin were studied by differential scanning calorimetry (DSC). The curing kinetics equation of BA221 resin and optimized curing system were obtained. The activation energy of BA221 resin is decreased 66.9% than CE resin. The viscosity variation of BA221 resin was researched by rheological method. The film forming temperature of hot-melt BA221 resin is determined to be 80 ℃. A hot-melt film with good film forming and ductility was obtained. The glass transition temperature of BA221 resin is 268.4 ℃.The tensile strength and elongation are 79.7 MPa and 3%,and its bending strength and impact strength are 122 MPa and 21 kJ/m².Comparing with CE resin, it is increased by 96.3%,134.4%,76% and 270%, respectively. The results of scanning electron microscopy (SEM) show that the cured BA221 resin exhibits ductile fracture. F-51 phenolic epoxy modified CE resin has significant effects, achieving the engineering application goals of prepolymerization at 120 ℃,film formation at 80 ℃,and post curing at 180 ℃.It provides a high temperature resistant CE resin for the preparation of hot melt prepregs.