石墨烯对环氧镍系导电胶导电性的影响研究

Effects of graphene on conductivity of epoxy/nickel conductive adhesive

以环氧树脂为基体树脂、镍粉为主要导电填料、石墨烯为辅助导电填料、改性聚酰胺为固化剂,制备了环氧镍系导电胶。探讨了导电胶体系中镍粉的最佳比例及添加石墨烯对环氧镍系导电胶的性能影响规律。研究结果表明:采用研磨工艺制得镍粉质量分数为74%(导电胶的所有组分混合后,除去溶剂的质量,镍粉的占比为74%)时,镍系导电胶的导电性能较优,其电阻率可达9.5×10-3Ω·cm;通过添加石墨烯可有效地降低导电胶的体积电阻率,并增强导电胶的抗老化性;当w(石墨烯)=1.0%时(相对于总质量而言),镍系导电胶的体积电阻率降至7.8×10-4Ω·cm;经过1 000 h湿热老化试验后,未掺杂石墨烯的镍系导电胶的体积电阻率上升了42%,而掺杂石墨烯的镍系导电胶的体积电阻率仅上升了5%。

Epoxy/nickel conductive adhesive was prepared by using epoxy resin as matrix resin,nickel powder as main conductive filler,graphene as auxiliary filler and modified polyamide as curing agent.The optimum proportion of nickel powder in conductive adhesive system and the effects of graphene addition on the performance of epoxy/nickel conductive adhesive were investigated.The research results showed that when the mass fraction of nickel powder prepared by grinding process was 74%(After all the components of conductive adhesive were mixed,the mass of the solvent was removed,and the proportion of nickel powder was 74%),the conductive performance of nickel conductive adhesive was relatively excellent,and its resistivity could reach 9.5×10-3Ω ·cm.By adding graphene,the volume resistivity of conductive adhesive could be effectively reduced,and the aging resistance of conductive adhesive could be enhanced.When w(graphene)=1.0%(relative to the total mass),the volume resistivity of nickel conductive adhesive decreased to 7.8×10-4Ω·cm.After 1 000 h heat and humidity aging test,the volume resistivity of nickel conductive adhesive without graphene increased by 42%,while the volume resistivity of nickel conductive adhesive mixed with graphene increased by only 5%.