CTBN/PI复合改性环氧树脂的结构与性能

摘要

采用端羧基丁腈橡胶(CTBN)和聚酰亚胺树脂(P1)为改性剂,甲基六氢苯酐(MeHHPA)为固化剂,2,4,6-三(二甲氨基甲基p)苯酚(DMP-30)为固化促进剂,对双酚A型环氧树脂(DGEBA)进行改性,研究了CTBN/PI复合改性剂对DGEBA力学性能、动态热力学性能和形态结构的影响.结果表明,CTBN/PI复合改性剂在保持弹性模量损失很小的情况下,显著提高了DGEBA的冲击强度、断裂强度和断裂伸长率;当复合改性体系中CTBN和PI添加量分别为20～30份、1.5～2.0份(质量份,下同)时,体系的综合力学性能最佳;适当引入PI增加了体系储能模量和耐热性;DGEBA的冲击断面发生了塑性变形,韧性得到了改善.%A diglycidyl ether of bisphenol-A type epoxy resin (DGEBA) was modified by using liquid carboxyl-terminated butadiene acrylonitrile rubber (CTBN) and polyimide (PI) as combining impact modifiers,methylhexahydrophthalic anhydride (MeHHPA) as a curing agent and 2,4,6-tris(dimethylaminomethyl) phenol as a curing accelerator.The effects of CTBN and PI on the mechanical properties,dynamic mechanical properties and morphology of DGEBA were investigated.The results indicated that the Izod impact strength,fracture strength and elongation at break of DGEBA were significantly increased,while the modulus decreased slightly.The modified DGEBA achieved optimum mechanical properties when 20～30 phr of CTBN and 1.5～2.0 phr of PI were incorporated.Moreover,the presence of PI in an appropriate amount could enhance the storage modulus and heat resistance of DGEBA.The scanning electron microscopic observation indicated that the toughening effect was attributed to the plastic deformation of fracture surface.