Abstract: Glass fabric-reinforced benzoxazine prepregs were prepared by hot melt impregnation. The process and thermogravimetry of the benzoxazine resin were studied. And the dynamic thermomechanic analysis, mechanical retaining at high temperature and flame retardant properties of the prepregs were also investigated. The softening point of the benzoxazine resin was 41~42℃ and the lowest viscosity was 1835 mPa·s, which were suitable for the preparation of prepregs. In nitrogen atmosphere, the initial degradation temperature of benzoxazine resin was about 280℃, and the char yield was about 61.3% at 800℃. The mechanical and interface properties of the SW280 fabric/benzoxazine prepregs were excellent. The Tg of the composite was about 200℃. The retention ratios of the compression strength,flexural strength, flexural modulus, and interlaminar shear strength at 200℃ were 90.6%, 59.4%, 83.2%, and 62.7%, respectively. The flame retardancy of the composites was excellent. The maximal smoke density was 0. The oxygen index was ＞58%. The vertical burning level was V-1.

Key words: benzoxazine resin, hot-melt prepregs, process, mechanical properties, flame retardancy