交联剂和炭黑添加量对半导电屏蔽料性能影响
Effects of Crosslinking Agentsand Carbon Black Content on the Performance of Semi-Conductive Shielding Materials
-
摘要: 为研究交联剂和炭黑(carbon black,CB)添加量对半导电屏蔽料性能的影响,以导电炭黑为填料、乙烯-丙烯酸丁酯共聚物(ethylene-butyl acrylate,EBA)为基体和2,4-二叔丁基过氧化异丙苯(BIBP)为交联剂,采用熔融共混、交联制备了高压电缆半导电屏蔽料。研究BIBP和CB添加量对半导电屏蔽料热延伸、体积电阻率、机械性能和流变性能的影响。EBA为70 phr,导电炭黑为30 phr时,随着BIBP添加量提高,半导电屏蔽料热延伸伸长率和永久变形率降低,体积电阻率增大,抗拉强度逐步提高,断裂伸长率先增大后减小,熔融指数增大,BIBP为1.0 phr时,综合性能最优。EBA为70 phr,BIBP为1.0 phr时,随着CB添加量增加,半导电屏蔽料的体积电阻率逐渐降低。当CB添加量增至25 phr时,达到其逾渗阈值,半导电屏蔽料体积电阻率急剧下降。CB添加量为35 phr,半导电屏蔽料在25、90 ℃体积电阻率分别为4.3 Ω·cm和16.2 Ω·cm。此时正温度效应(positive temperature coefficient,PTC)系数为0.82,抑制PTC的效果最好。随着CB添加量增加,半导电屏蔽料的拉伸强度变化不明显,而断裂伸长率逐渐降低。即EBA为70 phr,BIBP为1.0 phr时,导电炭黑添加量在20~35 phr范围时,半导电屏蔽料的机械性能均满足国标要求。Abstract: To investigate the effects of the cross-linking agent and carbon black (CB) content on the characteristics of semi-conductive shielding materials for high-voltage cable, a blend was prepared by incorporating conductive CB as the filler, ethylene butyl acrylate copolymer as the matrix and 2,4-di-tert-butylcumyl peroxide (BIBP) as the cross-linking agent via melt blending and crosslinking. The influences of BIBP and CB content on the thermal elongation, volume resistivity, mechanical properties and rheological performance of the semi-conductive shielding materials were studied. With EBA at 70 phr and CB at 30 phr, as the BIBP content increases, the thermal elongation and permanent deformation rate of the semi-conductive shielding material decrease, while the volume resistivity increases and the tensile strength gradually improves. The elongation at break initially rises and then declines, and the melt flow index increases. When the BIBP addition amount is 1.0 phr, the overall performance is optimal. With EBA at 70 phr and BIBP at 1.0 phr, as the CB content increases, the volume resistivity of the semi-conductive shielding material gradually decreases. When the CB content increases to 25 phr, reaching its percolation threshold, the volume resistivity of the semi-conductive shielding material drops sharply. When the CB content is 35 phr, the volume resistivity of the semi-conductive shielding material is 4.3 Ω·cm and 16.2 Ω·cm at 25 ℃ and 90 ℃, respectively. Simultaneously, the positive temperature coefficient (PTC) is 0.82, indicating the best suppression effect on PTC. As the CB content increases, the tensile strength remains relatively stable, while the elongation at break gradually decreases. When the CB content is in the range of 20-35 phr, the mechanical properties meet the national standard requirements.
©上海电缆研究所有限公司《电线电缆》编辑部版权所有,未经授权不得转载、改编。

下载: