电缆附件用液态硅橡胶绝缘材料性能对比
Properties Comparison of Liquid Silicone Rubber Insulation Materials for Typical Cable Accessories at Home and Abroad
-
摘要: 为评估国内外典型电缆附件用液态硅橡胶(liquid silicone rubber,LSR)绝缘材料电气性能与力学性能的差异,以及二次硫化和热老化处理对材料性能的影响,选取国内外不同厂家生产的LSR材料为研究对象,对二次硫化前后及热老化前后的电气、力学性能进行了系统测试与分析。结果表明:二次硫化后,国产与进口材料的体积电阻率均显著提升;国产材料击穿电压强度小幅提升,撕裂强度增幅达79.2%~113%,拉伸强度均超过10 MPa,断裂伸长率为750%~800%,均高于进口材料;进口材料击穿电压强度普遍下降,最大降幅约8.1%,撕裂强度仅略微升高。热老化后,两类材料体积电阻率均呈分化趋势;国产材料击穿电压强度下降8.2%~10.3%,拉伸性能基本稳定,撕裂强度衰减约14%;进口材料击穿电压强度和撕裂强度部分不降反升,增幅分别为6.9%~14.4%和45%~50%,但断裂伸长率显著衰减,最大降幅达29.3%。综合测试数据表明,两类材料经二次硫化后的击穿电压强度均处于25~28 kV·mm−1区间,国产材料的拉伸强度、断裂伸长率及老化后力学性能保持率高于进口材料,进口材料的体积电阻率上限高于国产材料。研究结果可为电缆附件选材与工艺优化提供数据参考。Abstract: In order to evaluate the differences in electrical and mechanical properties between typical domestic and imported liquid silicone rubber (LSR) for cable accessories, LSR specimens from different domestic and foreign manufacturers were adopted as research objects. The influences of secondary vulcanization and thermal aging on the electrical and mechanical properties of domestic and imported materials were systematically investigated. The results indicate that after secondary vulcanization, the electrical breakdown strength of domestic LSR shows no obvious variation, while the volume resistivity and tear strength are greatly enhanced, with the increment of tear strength ranging from 79.2% to 113%. The tensile properties of domestic materials either rise or decline, and their overall mechanical properties are superior to those of imported ones. For imported LSR, although the volume resistivity is remarkably improved, the electrical breakdown strength generally decreases with a maximum reduction of approximately 8.1%. The tensile properties of a few materials have declined, and the initial crosslinking structure is already relatively complete, leaving limited room for improvement in tear strength. After thermal aging, the volume resistivity of both domestic and imported LSR partially increases and partially decreases. The electrical breakdown strength of domestic materials slightly declines, their tensile properties remain generally stable, and the tear strength undergoes attenuation. For imported materials, both the electrical breakdown strength and tear strength partially decrease while some increase reversely; the tensile strength stays stable but the elongation at break decreases significantly, with a maximum reduction of 29.3%. This work provides data support and theoretical basis for material selection and process optimization of cable accessories, and presents important engineering application value.
©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: