摘要
为满足新能源汽车对电机绝缘材料耐热性能提出的更高要求,并解决传统聚酰亚胺绝缘漆黏度大、加工性能欠缺的问题,本文基于丁酸(BA)与芳香胺的中和反应制备了“潜伏性”中间体,并将其引入酸酐封端的均苯四甲酸二酐-4,4',-二氨基二苯醚(PMDA-ODA)齐聚物中,随后加入4-氨基苯甲酸-4-氨基苯酯(APAB),得到不同单体比例配方制备的高耐热PI绝缘漆及漆膜。然后研究不同APAB含量及热处理温度对PI漆膜力学性能、耐热性能及介电性能的影响规律,并结合Materials Studio软件模拟解释分子链刚性对漆膜性能的具体作用。结果表明:“潜伏性”中间体能够在温度驱动下继续与PMDA反应形成PI;APAB的适量引入可降低分子链的运动能力,减小分子链间距,有效抑制次级弛豫;提高固化温度可促进分子链间交联;高耐热PI漆膜具有优异的耐热性能、力学性能及电学性能,拉伸强度超过147 MPa,玻璃化转变温度大于420℃,常温、1 kHz下漆膜的介电常数低于3.48,介质损耗因数低于0.019,且具有优异的介电温度稳定性和较高的电气强度(304.3~356.5 MV/m)。
To meet the higher requirements for heat resistance of motor insulation materials in new energy vehicles and address the issues of high viscosity and inadequate processability in traditional polyimide insulation varnishes,in this study,we prepared a"latent"intermediate based on the neutralization reaction between butyric acid(BA)and aromatic amines.This intermediate was introduced into an anhydride-terminated pyromellitic dianhydride-4,4′-diaminodiphenyl ether(PMDA-ODA)oligomer,followed by the addition of 4-aminobenzoic acid-4-aminophenyl ester(APAB),to synthesize high heat-resistant PI insulating varnishes and corresponding films with different monomer ratios.The effects of APAB content and heat treatment temperature on the mechanical properties,heat resistance,and dielectric properties of the PI films were investigated.In addition,Materials Studio software simulations was employed to explain the specific influence of molecular chain rigidity on film performance.The results show that the"latent"intermediate can continue to react with PMDA under thermal activation to form the PI.Appropriate incorporation of APAB restricts the movement ability of molecular chain,reduces spacing of molecular chains,and effectively suppresses secondary relaxation.The increase of curing temperature can promote cross-linking between molecular chains.The high heat-resistant PI films exhibit excellent heat resistance,mechanical properties,and electrical properties:tensile strength exceeds 147 MPa,glass transition temperature(Tg)is greater than 420℃,and at room temperature and 1 kHz,the dielectric constant remains below 3.48 with a dielectric loss factor below 0.019.The films also show excellent dielectric temperature stability and high electrical strength,ranging from 304.3 to 356.5 MV/m.
作者
严盈
李琇廷
许青松
董杰
赵昕
张清华
YAN Ying;LI Xiuting;XU Qingsong;DONG Jie;ZHAO Xin;ZHANG Qinghua(State Key Laboratory of Advanced Fiber Materials,College of Materials Science and Engineering,Donghua University,Shanghai 201620,China)
出处
《绝缘材料》
北大核心
2025年第12期21-29,共9页
Insulating Materials
基金
国家重点研发计划(2023YFB3811903)
国家自然科学基金资助项目(52203033)。
关键词
聚酰亚胺
绝缘漆
低黏度
耐热性能
介电温度稳定性
polyimide
insulating varnish
low viscosity
heat resistance
dielectric temperature stability
