Abstract Blends of polyethylene (PE) with nanocomposites of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene grafted maleic anhydride (SEBS-MA) thermoplastic elastomer filled with Zinc Oxide (ZnO) nanoparticles have been studied as potential candidates for applications in HV insulation systems including HVDC cables. In particular, the dielectric and mechanical properties of PE/SEBS-MA/ZnO blend nanocomposites have been evaluated and compared to those of PE/ZnO homopolymer nanocomposites prepared as a reference. PE/ZnO materials were characterized by homogeneous distribution of nanoparticles and presence of agglomerations attributed to insufficient compatibility between the metal oxide nanoparticles and the polyolefin matrix. However, nanoscale dispersion was achieved in SEBS-MA/ZnO and PE/SEBS-MA/ZnO nanocomposites due to improved compatibility between the nanoparticles and SEBS-MA. Besides, in PE/SEBS-MA/ZnO blend nanocomposites, ZnO nanoparticles remained exclusively confined in SEBS-MA or at the interface between PE and SEBS-MA. In terms of dielectric properties, the unfilled blend PE/SEBS-MA featured reduced breakdown strength and resistance to surface erosion by partial discharges in comparison with neat PE. However, upon addition of ZnO the blend PE/SEBS-MA presented higher performance when compared to PE. At 1 wt% ZnO loading, the resistance to surface erosion of PE/SEBS-MA increased by 45% higher than neat PE/SEBS-MA, 38% higher than unfilled PE and 30% higher PE/ZnO nanocomposite containing the same ZnO loading. Besides, blend nanocomposites exhibited dielectric losses lower than PE/ZnO nanocomposites at power frequencies and temperatures up to 80 °C. The breakdown strength of both sets of nanocomposites decreased compared to unfilled materials, at large loadings of nanoparticles. However, smaller reduction was observed in the case of PE/SEBS-MA/ZnO nanocomposites due to improved nanoparticles dispersion. Finally, PE/SEBS-MA/ZnO nanocomposites featured enhanced mechanical flexibility when compared to PE/ZnO nanocomposites.

中文翻译：

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用于高压绝缘应用的聚乙烯/热塑性弹性体/氧化锌纳米复合材料：介电、机械和流变行为

摘要 聚乙烯 (PE) 与填充有氧化锌 (ZnO) 纳米颗粒的聚苯乙烯-b-聚(乙烯-共-丁烯)-b-聚苯乙烯接枝马来酸酐 (SEBS-MA) 热塑性弹性体纳米复合材料的共混物已被研究作为潜在的候选物。适用于高压绝缘系统，包括高压直流电缆。特别是，PE/SEBS-MA/ZnO 共混纳米复合材料的介电和机械性能已经过评估，并与作为参考制备的 PE/ZnO 均聚物纳米复合材料进行了比较。PE/ZnO 材料的特征在于纳米颗粒的均匀分布和由于金属氧化物纳米颗粒和聚烯烃基体之间的相容性不足而导致的团聚。然而，由于纳米颗粒和 SEBS-MA 之间的相容性得到改善，在 SEBS-MA/ZnO 和 PE/SEBS-MA/ZnO 纳米复合材料中实现了纳米级分散。此外，在 PE/SEBS-MA/ZnO 共混纳米复合材料中，ZnO 纳米颗粒仅局限于 SEBS-MA 或 PE 和 SEBS-MA 之间的界面。在介电性能方面，与纯 PE 相比，未填充的 PE/SEBS-MA 混合物的击穿强度和抗局部放电表面侵蚀能力降低。然而，与 PE 相比，添加 ZnO 后，PE/SEBS-MA 共混物表现出更高的性能。在 1 wt% ZnO 负载下，PE/SEBS-MA 的抗表面侵蚀性比纯 PE/SEBS-MA 高 45%，比未填充 PE 高 38%，含有相同 ZnO 负载的 PE/ZnO 纳米复合材料高 30% . 除了，混合纳米复合材料在功率频率和高达 80°C 的温度下表现出低于 PE/ZnO 纳米复合材料的介电损耗。与未填充材料相比，在大量纳米颗粒负载下，两组纳米复合材料的击穿强度均降低。然而，由于改进的纳米粒子分散，在 PE/SEBS-MA/ZnO 纳米复合材料的情况下观察到较小的减少。最后，与 PE/ZnO 纳米复合材料相比，PE/SEBS-MA/ZnO 纳米复合材料具有增强的机械柔韧性。