三元乙丙橡胶自熔式绝缘拉伸性能和介电性能的老化演变规律  

Ageing evolution of tensile and dielectric properties of ethylene propylene diene monomer self-fusing insulation

作　　者：王强 李昊泽 李秀峰[1] 丁志鹏 白鑫宇 刘迪 王靖然 WANG Qiang;LI Haoze;LI Xiufeng;DING Zhipeng;BAI Xinyu;LIU Di;WANG Jingran(College of Electric and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;State Grid Zibo Huantai Power Supply Company,Zibo 256400,China)

机构地区：[1]山东理工大学电气与电子工程学院,山东淄博255000 [2]国网淄博桓台供电公司,山东淄博256400

出　　处：《绝缘材料》2025年第4期52-61,共10页Insulating Materials

基　　金：山东省自然科学基金资助项目(ZR2023ME129)。

摘　　要：为了研究热-力联合作用对三元乙丙橡胶自熔式绝缘性能的影响,本文对三元乙丙橡胶自熔式绝缘开展了不同温度和拉伸率的老化实验,分别对老化试样的拉伸性能和介电性能进行表征。结果表明:在老化过程中,试样因分子结构逐渐被破坏及黏胶分子的溶胀作用,其拉伸强度、断裂伸长率下降,且较强的拉伸应力会加剧老化程度,使缺陷逐渐发展扩大,进一步劣化试样的力学性能。随老化时间的增加,试样内部的极性基团不断增多,转向极化增强,极化损耗增加。当拉伸率逐渐增大时,试样的相对介电常数和介质损耗因数的增大速率呈现“先慢后快”的趋势,同时分子链断裂和微观缺陷的产生使载流子的浓度增大,且较大的拉伸率使分子间作用力减弱,势垒能级降低,载流子更易迁移,导致其体积电导率持续升高。在老化后期,拉伸应力下的分子链裂解严重,基体热膨胀使自由体积增大,导致电气强度下降,较大的拉伸率会进一步降低试样内部的陷阱能级,使电气强度的下降幅度更大。In order to investigate the effect of combined heat-force on the performance of ethylene propylene diene monomer self-fusing insulation,ageing experiments with different temperatures and tensile rates were conducted on the ethylene propylene diene monomer self-fusing insulation,and the tensile and dielectric properties of ageing samples were characterized respectively.The results show that during the ageing process,the tensile strength and elongation at break of the sample decrease due to the gradual destruction of molecular structure and swelling of adhesive molecules,and the strong tensile stress will exacerbate the degree of ageing,make the defects gradually develop and expand,and further deteriorate the mechanical properties of the sample.With the increase of ageing time,the polar groups inside the sample increases,the steering polarisation enhances,and the polarisation loss increases.When the stretching rate gradually increases,the increasing rates of relative dielectric constant and dielectric loss factor show the trend of“slow first and fast later”.At the same time,the breakage of molecular chains and the generation of microscopic defects increase the concentration of carrier,and the larger tensile rate weakens the intermolecular forces,reduces the barrier energy level,and makes the carriers easier to migrate,resulting in a continues increase of its volume conductivity.In the later stages of ageing,the molecular chain cleavage under tensile stress is serious,and the thermal expansion of the matrix increases the free volume,leading to a decrease in electric strength.A larger tensile rate will further reduce the trap energy level inside the sample,resgreater decrease in electric strength.

关 键 词：三元乙丙橡胶自熔式绝缘 热-力联合老化 拉伸性能 介电性能 

分 类 号：TM215[一般工业技术—材料科学与工程]