School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China.
Molecules. 2023 Jun 22;28(13):4908. doi: 10.3390/molecules28134908.
Direct current (DC) power transmission systems have received great attention because it can easily integrate many types of renewable energies and have low energy loss in long-distance and large-capacity power transmission for electricity global sharing. Nanoparticles (NPs) have a positive effect on the insulation properties of polymers, but weak interaction between NPs and polymer matrix greatly decreases the effort of NPs on the enhancement of insulation properties, and thereby limits its engineering application. In this work, grafting strategy was used to link the modified NPs and polymer matrix to improve their interactions. Silica NPs (SiO-NPs) were modified by 3-(methacrylyloxy) propyl-trimethoxysilane (MPS) to introduce highly active groups on the SiO-NPs surface, followed by the pre-irradiated linear low-density polyethylene (LLDPE) being easily grafted onto the MPS modified SiO-NPs (MPS-SiO-NPs) in the melt blending process to obtain LLDPE-g-MPS-SiO-NPs nanocomposites. Fourier-transform infrared (FT-IR) spectrum and X-ray photoelectron spectroscopy (XPS) confirm the successful incorporation of MPS into SiO-NPs. Transmission electron microscopy (TEM) verifies that the modified SiO-NPs exhibits more uniform distribution. The rheology result shows that the interaction between MPS-SiO-NPs and LLDPE significantly improves. More importantly, the LLDPE-g-MPS-SiO-NPs nanocomposites displays superior DC breakdown strength to that fabricated by conventional modification methods. When the addition of MPS-SiO-NPs is 0.1 wt%, the highest DC breakdown strength values of 525 kV/mm and 372 kV/mm are obtained at 30 °C and 70 °C, respectively, and high DC breakdown strength can be well maintained in a wide loading range of NPs.
直流（DC）输电系统因其能够方便地集成多种可再生能源，并且在远距离、大容量输电时能量损耗低，有利于实现电力的全球共享，而受到了广泛关注。纳米粒子（NPs）对聚合物的绝缘性能有积极影响，但 NPs 与聚合物基体之间的弱相互作用大大降低了 NPs 增强绝缘性能的效果，从而限制了其工程应用。在这项工作中，采用接枝策略将改性 NPs 和聚合物基体连接起来，以改善它们之间的相互作用。首先用 3-（甲基丙烯酰氧基）丙基三甲氧基硅烷（MPS）对二氧化硅 NPs（SiO-NPs）进行改性，在 SiO-NPs 表面引入高活性基团，然后在熔融共混过程中，预先辐照线性低密度聚乙烯（LLDPE）容易接枝到 MPS 改性的 SiO-NPs（MPS-SiO-NPs）上，得到 LLDPE-g-MPS-SiO-NPs 纳米复合材料。傅里叶变换红外（FT-IR）光谱和 X 射线光电子能谱（XPS）证实了 MPS 成功地掺入到 SiO-NPs 中。透射电子显微镜（TEM）验证了改性 SiO-NPs 分布更加均匀。流变学结果表明，MPS-SiO-NPs 与 LLDPE 之间的相互作用显著增强。更重要的是，与传统改性方法制备的复合材料相比，LLDPE-g-MPS-SiO-NPs 纳米复合材料具有更优异的直流击穿强度。当添加量为 0.1wt%时，在 30°C 和 70°C 下，复合材料的直流击穿强度分别达到 525kV/mm 和 372kV/mm 的最高值，并且在 NPs 较宽的填充范围内仍能保持较高的直流击穿强度。
