具有电弧猝熄功能可瓷化硅橡胶的制备及其耐漏电起痕性能与机理研究

How to effectively improve the anti-tracking and anti-flashover properties of silicone rubber, is one of the key problems to be resolved in the development and application of high performance silicone rubber insulating materials. In this work, fluorine-containing vinyl MQ silicone resin (FVMQ) is firstly synthesized by fluorine-containing siloxane, vinyl disiloxane and tetraethoxysilane by sol-gel reaction. Secondly, ceramic precursor (CP) with high ceramic conversion rate is prepared by 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, tetraethoxysilane, boric acid and ultrafine low melting point glass powder via in-situ condensation reaction and encapsulation. Subsequently, FVMQ and CP are incorporated into the addition type liquid silicone rubber, and the excellent anti-tracking performance silicon rubber with ceramifiable and arc-quenching capability is obtained via hydrosilylation reaction. It is worth noting that this proposal makes good use of the hydrophobic anti-fouling and arc-quenching capability of FVMQ, as well as the co-ceramified effect between silicone rubber and CP. Especially, the hydrophobic anti-fouling, arc-quenching and ceramifiable capability are effectively coupled in a novel way. By the combination of the prevention and cure measure, the silicone rubber is endowed with efficient anti-tracking and anti-flashover properties. In addition, the anti-tracking mechanism of the silicone rubber is further studied and revealed, which is beneficial to develop and break through the existing polymer anti-tracking theory. Through this research, the new ideas and theoretical basis should be provided for the design, preparation and application of the novel polymer insulating material with high anti-tracking property.

如何有效提高硅橡胶的耐漏电起痕性能及防污闪能力，是当前高性能硅橡胶绝缘材料发展与应用所亟需解决的关键问题之一。本项目以含氟硅氧烷、正硅酸乙酯和乙烯基二硅氧烷等为原料，通过溶胶-凝胶法合成含氟乙烯基MQ硅树脂（FVMQ）；其次采用四甲基四乙烯基环四硅氧烷、正硅酸乙酯和硼酸等经原位缩合反应包覆超细低熔点玻璃，制备高瓷化率的陶瓷前躯体（CP）；将FVMQ、CP等引入加成型液体硅橡胶中，通过硅氢加成反应制备具有电弧猝熄功能的可瓷化硅橡胶绝缘材料。本项目巧妙利用了FVMQ良好的憎水防污性和电弧猝熄功能，以及硅橡胶与CP的共瓷化作用，将憎水防污、电弧猝熄和表面陶瓷化功能有机耦合，赋予硅橡胶高效的耐漏电起痕性能及防污闪能力。在此基础上，深入研究它们之间的协同作用并揭示其耐漏电起痕机理，可对现有聚合物耐漏电起痕理论进行创新和突破，为新型高性能聚合物绝缘材料的设计、制备及应用提供新方法和理论依据。

硅橡胶的漏电起痕破坏严重威胁高压超高压输变电路的安全与稳定。如何有效提高硅橡胶的耐漏电起痕性能及防污闪能力，是当前高性能硅橡胶绝缘材料发展与应用亟需解决的关键问题。在本项目中，我们巧妙利用含氟乙烯基MQ硅树脂（FVMQ）良好的憎水防污性和电弧猝熄功能，以及硅橡胶与陶瓷前躯体的共瓷化作用，将憎水防污、电弧猝熄和表面陶瓷化功能有机耦合，赋予硅橡胶高效的耐漏电起痕性能及防污闪能力。项目以含氟硅氧烷、乙烯基硅氧烷和正硅酸乙酯等通过溶胶-凝胶法制备含氟乙烯基MQ硅树脂（FVMQ）；采用环四硅氧烷、正硅酸乙酯和硼酸等为原料，经缩合反应合成高瓷化率有机硅-硼陶瓷前躯体（PBSil）；将FVMQ、PBSil与加成型液体硅橡胶（ALSR）等混合均匀，通过硅氢加成反应制备了兼具高耐漏电起痕性能、良好阻燃性能和力学性能的硅橡胶绝缘材料。FVMQ/PBSil可有效提高ALSR的热稳定性能和抗电蚀损能力，减少干带电弧的发生频率，并促进硅橡胶表面在高压电弧作用下交联瓷化形成坚实致密的陶瓷阻隔层，有效抑制电痕的产生和发展。当FVMQ和PBSil的用量分别为5.0phr和1.5phr时，即可使ALSR通过1A4.5kV等级的耐漏电起痕测试。在此基础上，进一步阐明了电弧猝熄与表面陶瓷化的协同作用并揭示其耐漏电起痕机理，为新型高性能聚合物绝缘材料的设计、制备及应用提供了新方法和理论依据。在项目执行过程中，课题组在ACS Applied Materials & Interfaces, Polymer Degradation and Stability, Applied Surface Science和IEEE Transactions on Dielectrics and Electrical Insulation等本领域权威刊物上发表学术论文20篇（其中SCI收录18篇，EI收录1篇），授权中国发明专利4项，新申请6项。协助培养博士生2名，硕士生2名，本科生2名。