聚酰亚胺表面处理玻璃纤维/环氧树脂复合材料力学性能

采用浇铸成型工艺制备含0.5wt%、长度分别为1 mm、3 mm、5 mm的短切玻璃纤维/环氧树脂（GF/EP）复合材料，研究含活性酚羟基和不含酚羟基的两种聚酰亚胺（PI）处理GF表面对纤维束拉伸强度及GF/EP复合材料力学性能的影响，并进一步研究PI处理GF对复合材料热性能的影响。研究结果表明，经过PI处理的GF，集束性和拉伸强度得到提高。含活性酚羟基聚酰亚胺（PI1）处理的GF拉伸强度由原丝束的517 MPa提高到1 032 MPa，不含酚羟基聚酰亚胺（PI2）处理的GF提高到986 MPa。当PI1处理的GF长度为3 mm时，GF/EP复合材料的力学性能最好，拉伸强度比未处理的提高23.62%，拉伸模量提高34.03%，弯曲强度提高28.74%，断裂韧性提高13.04%；PI2处理的GF，GF/EP复合材料拉伸强度提高15.87%，拉伸模量提高23.70%，弯曲强度提高14.11%，断裂韧性提高4.05%。此外，PI处理GF对GF/EP复合材料热性能也有一定程度的提高。

Mechanical properties of polyimide surface treated glass fiber/epoxy resin composites

The short glass fiber/epoxy resin (GF/EP) composites with 0.5wt% GF were fabricated through casting method. The properties of GF/EP composites length 1 mm, 3 mm and 5 mm were studied, respectively. The mechanical properties and thermal properties of GF/EP composite and the tensile strength of the fiber tow with surface treatment of polyimide (PI) were investigated. Polyimides with reactive phenolic hydroxyl groups (PI1) and without (PI2) were prepared. The results show that tensile strength and strand integrity of the GF are improved. The tensile strength of GF treated with PI1 is increased from 517 MPa to 1 032 MPa and PI2 is increased to 986 MPa. GF/EP composites have the best mechanical properties when 3 mm GF treated with PI1, and tensile strength, tensile modulus, flexural strength and fracture toughness of PI1-GF/EP composites are increased by 23.62%, 34.03%, 28.74% and 13.04% respectively. The mechanical properties of GF/EP composites with treatment of PI2 are slightly improved. The tensile strength, tensile modulus, flexural strength and fracture toughness are increased by 15.87%, 23.70%, 14.11% and 4.05%, respectively. The glass transition temperature of PI2-GF/EP composite is significantly improved by treating GF with PI.