离子导体结构胶的环境可靠性研究

Study on environmental reliability of ionic conductor structural adhesive

通过将聚乙二醇(PEG1000)与1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺离子液体([BMIM] TFSI)引入环氧胶粘剂,制备了一种通电可快速剥离的高强度离子导体环氧结构胶(I-EP)。其初始粘接强度达21.65 MPa,通电60 V/60 s后残余强度仅为0.02 MPa,剥离效率可达99.91%。重点研究了温度为55℃、相对湿度为95%RH的老化环境对I-EP粘接强度的影响。研究结果表明:在此环境下老化48 h后,I-EP的粘接强度衰减了49.28%;对其环境可靠性的失效机制研究发现,在高温、高湿环境下,I-EP本体中的[BMIM]TFSI容易向粘接界面发生物理迁移,与粘接基材发生自发的电化学腐蚀,导致胶粘剂与基材之间的强相互作用被破坏,进而导致粘接强度明显下降。

A kind of high-strength ionic conductor epoxy structural adhesive that could be quickly peeled off by electricity was prepared by introducing polyethylene glycol(PEG1000)and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide([BMIM]TFSI)into epoxy adhesive.The initial bonding strength reached21.65 MPa,the residual strength was only 0.02 MPa after applying 60 V/60 s,and the peeling efficiency was99.91%.The influence of aging environment with temperature of 55℃and relative humidity of 95%RH on the bonding strength of I-EP was emphatically studied.The research results showed that the bonding strength of I-EP reduced by 49.28%after aging for 48 h in this environment.The study on the failure mechanism of its environmental reliability found that under high temperature and high humidity environment,[BMIM]TFSI in I-EP body was prone to physical migration to the bonding interface and spontaneous electrochemical corrosion with the bonding substrate,leading to the destruction of strong interaction between adhesive and substrate,which led to a significant decline in the bonding strength.