SiO_2中空微球对高温硫化硅橡胶电气绝缘性能的影响

Effect of Hollow Silica Spheres on Electrical Insulation Properties of High Temperature Vulcanized Silicone Rubber Composite

采用模板法制备了尺度均一的Si O_2中空微球(HSS),将其均匀分散于高温硫化硅橡胶(HTV)中制成HSS/HTV复合材料,分析了HSS的形貌及壁厚,考察了其对硅橡胶电气绝缘性能的影响及其与硅橡胶基体的相互作用.结果表明,HSS对硅橡胶的体积电阻率、击穿强度、介电常数及介电损耗均有较明显的影响,优于同等含量的气相Si O_2/HTV复合材料.加入HSS后,复合材料的体积电阻率由纯硅橡胶的5.3×1015Ω·cm提升至1017Ω·cm数量级,但随HSS含量增大略有下降;击穿强度随HSS含量增加而增大,含量为0.05 g/g时达21.6 k V/mm,比纯硅橡胶提高了26.3%;介电常数随HSS含量增大先降低后升高,含量为0.02 g/g时最低;介电损耗随HSS含量增大略有增大,但仍较低.

Hollow silica spheres （HSS） with uniform size were prepared and composed with high temperature vulcanized silicone rubber （HTV）. The microstructure of HSS was characterized, the interactions between molecular chain and the HSS was analyzed. Volume resistivity, breakdown strength, relative permittivity and dielectric loss of the HSS/HTV composites were tested. The results showed that, volume resistivity of the HSS/HTV composites was improved from 5.3×10^15Ω·cm to 10^17 Ω·cm level and will decrease slightly with the increasing of HSS. The breakdown strength increased with the filler loading increasing. Composite filled with 0.05 g/g HSS achieved a breakdown strength of 21.6 kV/mm which increased by 26.3% than pure HTV. Composite containing 0.02 g/g HSS achieved a lowest relative permittivity.