二酐结构对热固型聚酰亚胺性能的影响

Effects of dianhydride structure on the properties of thermosetting polyimide

基于4,4’-二氨基二苯醚(ODA)与4种不同结构的二酐合成了3-氨基苯乙炔(APA)封端的热固型聚酰亚胺(O-PI、B-PI、A-PI及F-PI),研究了二酐单体结构对其耐温性能及对钢板粘接强度的影响。研究结果表明:固化后的聚酰亚胺已亚胺化完全,且会影响到聚合物结晶度;4种聚酰亚胺的分解温度均在500℃以上,4种APA封端聚酰亚胺的耐温规律依次为B-PI>O-PI>A-PI>F-PI;常温下A-PI的拉伸剪切强度表现最佳,在高温区域下O-PI的剪切强度最大,在350和400℃下拉伸剪切强度分别高达6.67和5.42 MPa。综合热稳定性和粘接性能评价,O-PI为相对最佳产品,更能适应机械制造工业、微电子器件及航空航天等高新技术领域对耐高温和高粘接强度的要求。

The thermosetting polyimides(O-PI,B-PI,A-PI and F-PI)with 3-aminophenylacetylene(APA terminated were synthesized based on 4,4’-diaminodiphenyl ether(ODA)and four different structures of dianhydride.The effects of dianhydride monomer structure on temperature resistance and bonding strength of steel plate were investigated.The research results showed that the cured polyimide had been completely imidized and would affect the crystallinity of polymer.The decomposition temperature of four polyimides was all above 500 ℃,and the temperature resistance rule of four APA-terminated polyimides was B-PI>O-PI>A-PI>F-PI.The tensile shear strength of A-PI was the best at room temperature,while the shear strength of O-PI was the highest in the high temperature area,the tensile shear strength was as high as 6.67 and 5.42 MPa at 350 and 400 ℃,respectively.According to the comprehensive evaluation of thermal stability and bonding performance,O-PI was the relatively best product,which could better meet the requirements of high temperature resistance and high bonding strength in high-tech fields such as machinery manufacturing industry,microelectronic devices and aerospace.