聚酚氧/环氧树脂共改性氰酸酯树脂的制备及其低温性能

Preparation and Cryogenic Properties of Cyanate Ester Resin Blends Co-modified by Phenoxy Resin/Epoxy Resin

采用聚酚氧树脂(PKHH)和高纯环氧树脂(EP),通过熔融预聚的方式共改性氰酸酯树脂(CE),制备可在超低温环境中稳定使用的改性氰酸酯树脂。结果表明:PKHH能加速CE树脂固化反应;PKHH通过半互穿网络(SIPN)的增韧机理改善CE树脂的韧性;含有10%(质量分数)PKHH的CE/EP混合物在–196℃下的冲击强度为18.4 kJ/m^2,模量约为3.5 GPa;经14次冷-热循环后(–196~200℃),试样表面未见裂纹产生。

The modified cyanate ester resin（CE） which can be applied stably in the cryogenic environment was prepared by using phenoxy resin（PKHH） and high purity epoxy resin（EP） through the method of melting prepolymerization. The results show that the curing reaction of CE is accelerated by the addition of PKHH, but the reaction pathways are not changed. It is found that PKHH can improve the ductility by the mechanism of the semi-interpenetrating network （SIPN） in the cured CE networks. Especially, the impact strength value of the CE/EP blends with the content of 10% （mass fraction） PKHH reaches to 18.4 kJ/m2 and the modulus is maintained at about 3.5 GPa at –196 ℃, accordingly the cracks are not observed on the surface of specimens after 20 low-high temperature cycles （–196 to 200 ℃）.