本文报导端羧基丁腈橡胶/环氧E-51/2-乙基-4-甲基咪唑体系的研究工作。主要阐述该体系复合物的结构形态和主要力学性能,并根据拉伸应力-应变特征与双悬臂梁劈裂试伴的断裂面形态,分析讨论了橡胶增韧机理,同时提出了裂缝尖端钝化模型,推导了裂端临界曲率半径和断裂表面能的估算公式。 This paper reports the work of carboxyl terminated nitrile rubber / epoxy E-51/2-ethyl-4-methylimidazole system. The structure and main mechanical properties of the composites are mainly described. According to the tensile stress-strain characteristics and the fracture surface morphology of double-cantilever splitting partner, the toughening mechanism of rubber is analyzed and discussed. At the same time, the crack tip tip passivation Model, the formulas for calculating the critical radius of curvature and the fracture surface energy are derived.