中文摘要：

目的测试自行合成的聚酰亚胺与环氧树脂共混改性产物的力学性能,观察其断面显微形貌,以探索改性后的环氧树脂材料增强的效果。方法将自行合成的聚酰亚胺与E-51环氧树脂共混得到改性环氧树脂,按不同材料、不同配比分组后进行三点抗弯试验、剪切粘接强度测试和断面形态的扫描电镜观察。结果聚酰亚胺-环氧树脂共混产物抗弯强度最高可达（141.03±9.93）MPa,比纯环氧树脂（抗弯强度（112.05±8.81）MPa）提高了25.86%（P〈0.05）;断裂伸长为（2.06±0.24）mm,比纯环氧树脂的断裂伸长（1.54±0.24）mm提高了33.77%（P〈0.05）;改性后对弹性模量和粘接强度无明显变化（P〉0.05）。扫描电镜下可见聚酰亚胺-3改性的环氧树脂断面光滑,未见明显微裂纹。结论聚酰亚胺可用于环氧树脂的共混改性,在适当配比（25phr）下具有理想的增强效果。

英文摘要：

Object In this study the mechanical properties and fracture morphology of self-made polyimide-epoxy（PI/EP） composition was tested to investigate whether blending epoxy with polyimide was an effective way to strengthen epoxy. Methods The polyimide modified epoxy was grouped according to different modification and proportion, then characterized by 3 point bending test, shear-bonding test and scanning electron microscopy. Results The flexural strength of epoxy-polyimide blend could be as high as 141.03±9.93 MPa, which was 25.86% higher than the control group（112.05±8.81MPa）（P〈0.05）, and its breaking elongation（2.06±0.24mm） was 33.77% higher than the control group（1.54±0.24mm）（P〈0.05）, no significant difference was observed in flexural modulus and shear-bonding strength（P〉0.05）. The fracture morphology was smooth and no obvious crack was observed in the fracture surface. Conclusion Blending polyimide with epoxy in proper proportion（25phr） could be a workable way to strengthen epoxy.