交联剂和抗氧剂对低密度聚乙烯绝缘料熔体黏弹特性的影响  

Effect of Crosslinking Agent and Antioxidants on the Melt Viscoelastic Properties of Low-density Polyethylene Insulating Materials

作　　者：李加才 刘红剑 王诗航[1] 李盛涛[1] 潘东 汪胜和 LI Jiacai;LIU Hongjian;WANG Shihang;LI Shengtao;PAN Dong;WANG Shenghe(State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China;State Grid Anhui Electric Power Company,Hefei 230061,Anhui Province,China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049 [2]国网安徽省电力有限公司,安徽省合肥市230061

出　　处：《中国电机工程学报》2023年第1期368-379,共12页Proceedings of the CSEE

基　　金：国家电网有限公司总部管理科技项目(SGAH0000KJJS1900436);国家自然科学基金(重点项目)(U2066204)。

摘　　要：高压电缆用低密度聚乙烯(low-density polyethylene,LDPE)绝缘料熔体的黏弹特性决定了其挤出加工成型水平,研究交联剂和抗氧剂对其未交联时黏弹特性的影响规律与机制对于提升绝缘质量具有重要意义。该文以LDPE为基料,分别混制含过氧化二异丙苯(dicumyl peroxide,DCP)和3种不同抗氧剂的电缆绝缘料,使用旋转流变仪获得DCP和抗氧剂对自制绝缘料未交联时黏弹特性的影响规律,并从原子水平分析其微观影响机制。结果表明,添加少量的抗氧剂会对绝缘料黏弹特性产生显著的影响,且随着添加含量的增加,其复数黏度和动态模量均逐渐下降。由DCP和抗氧剂分子化学构成和拓扑结构的差异引起其对绝缘料黏弹特性的影响程度不同,即添加剂分子有效极性基团数量越多、分子尺寸越小、形状越趋向线型扁圆,对绝缘料黏弹特性的影响程度越大。该研究为深入理解交联剂和抗氧剂对高压电缆用LDPE绝缘料未交联时熔体黏弹特性的影响机制提供了理论参考。The melt viscoelastic properties of low-density polyethylene(LDPE) insulating materials used for high-voltage cables determine the extrusion molding level, so it is significant to study the effect and mechanism of crosslinking agent and antioxidants on its viscoelastic behavior under the uncross-linking condition for improving the insulation properties. In this paper, dicumyl peroxide(DCP) and three kinds of antioxidants are respectively mixed with LDPE as matrix materials to prepare the cable insulating materials. The effect of DCP and antioxidants on melt viscoelastic properties of cable insulating materials are obtained by rotational rheometer testing and its microcosmic mechanism is investigated from the atomic level. The results show that a small amounts of antioxidants have the more obvious influence on the viscoelastic properties of cable insulating materials comparing with DCP, and the complex viscosity and dynamic modulus of cable insulating materials gradually decline with the increase of additive content. Besides, crosslinking agent and different antioxidants have different effect degree on the melt viscoelastic properties of cable insulating materials, which is caused by chemical composition and topological structure of DCP and antioxidant molecules. The number of effective polar groups is more, the molecular size is smaller, and the shape tends to be more linear oblate, which generates more obvious effect on the viscoelastic properties of cable insulating materials. This study provides an important theoretical basis for further understanding the effect mechanism of crosslinking agent and antioxidants on melt viscoelastic properties of LDPE insulating materials used for high-voltage cables.

关 键 词：高压电缆 低密度聚乙烯 交联剂 抗氧剂 黏弹特性 分子模拟 

分 类 号：TM215[一般工业技术—材料科学与工程]