西安航天复合材料研究所 陕西省航天复合材料重点实验室，陕西 西安 710025
针对耐高温环氧树脂韧性低的问题，本文采用酚酞基聚芳醚酮（PEK-C）增韧改性耐高温环氧树脂。研究了PEK-C相对分子质量和含量对改性树脂的固化反应、增韧效果和耐热性能的影响。结果表明，PEK-C的加入对固化反应、耐热性能的影响较小，但会显著提升环氧树脂的韧性，且在一定范围内，PEK-C相对分子质量和添加量越大，增韧效果越好。15% 相对分子质量8×104的PEK-C改性树脂具有最佳力学性能，拉伸强度和断裂延伸率分别达到80 MPa和3.1%，较未改性树脂分别提高了68%和121%，冲击韧性高达23.3 kJ/m2，较未改性树脂提升了99%。采用透射电子显微镜表征了不同PEK-C含量改性树脂的微观相结构，结果表明，随PEK-C含量增加，依次观测到从海岛相到双连续再到相反转的相结构转变。
In view of the low toughness of high temperature epoxy resin, phenolphthalein-based polyaryletherketone (PEK-C) was adopted to toughen and modify high temperature epoxy resin. The effects of the molecular weight and content of PEK-C on the curing reaction, toughening effect and heat resistance of the modified resin were studied. The results show that the addition of PEK-C has little effect on the curing reaction and heat resistance, but it can significantly improve the toughness of the epoxy resin. The 15% PEK-C with the molecular weight of 8×104 modified resin has the best mechanical properties, the tensile strength and elongation at break reach 80 MPa and 3.1%, respectively, which are 68% and 121% higher than those of the unmodified resin, respectively. The impact toughness is ss high as 23.3 kJ/m2, which is 99% higher than that of the unmodified resin. The microphase structures of the modified resins with different PEK-C contents were characterized by transmission electron microscopy (TEM). With the increase of PEK-C content, the phase structure transition from sea-island phase to bicontinuous phase inversion was sequentially observed.