以聚酰亚胺短纤和沉析纤维为原料,通过湿法抄造结合热压和树脂浸渍的方法制备聚酰亚胺纤维/环氧树脂纸基复合材料,研究了热压温度、热压压力以及环氧树脂浸渍量对聚酰亚胺纸基复合材料性能的影响.结果表明,热压处理增加了聚酰亚胺纤维间的接触面积,使聚酰亚胺纤维纸的力学性能和电学性能增强;采用环氧树脂浸渍处理,可以进一步增加聚酰亚胺纸基复合材料的力学性能(抗张指数提高了1.25倍)和电学性能(耐压强度提高了17%);当热压温度为210℃、热压压力为120 N/mm、浸渍量为20%时,所制备的聚酰亚胺纸基复合材料具有较好的力学性能和电学性能,其抗张指数为57.5 N·m/g,撕裂指数为6.86 m N·m2/g,耐压强度为12.3 k V/mm,在航空航天、绝缘阻隔、环境保护等领域具有潜在的应用前景.
Polyimide fiber/epoxy paper-based composite materials were prepared from polyimide chopped fibers and polyimide fibrid fibers by means of wet papermaking combined with hot pressing and resin impregnation, and the effects of hot-pressing temperature, hot-pressing pressure and epoxy resin impregnation increment on the properties of polyimide fiber paper-based composite materials were investigated. The results show that ( 1) after the hot press-ing, the contact area of polyimide fibers increases, which results in the improvement of mechanical and electrical properties of the polyimide fiber paper; (2) resin impregnation further improves the mechanical and electrical pro-perties of polyimide fiber paper-based composite, concretely, the tensile index increases by 1. 25 fold and the die-lectric strength increases by 17% ; and (3) at a hot-pressing temperature of 210 °C , a hot-pressing pressure of 120 N/mm and an impregnation increment of 20% , the composite possesses good mechanical and electrical properties, namely a tensile index of 57. 5 Ntii/ g, a tear index of 6. 86 mN,m2/g and a dielectric strength of 12. 3 kV/mm, which means that the composite is potentially useful in such fields as aerospace, insulation barrier and environmen-tal protection.