预拉伸对硅橡胶介电性能的影响

以液体硅橡胶DC 186为基体，通过控制交联体系的用量制备了不同的硅橡胶薄膜材料，研究了交联程度对硅橡胶材料力学性能影响，研究了预拉伸程度和持续时间对硅橡胶材料介电性能的影响。结果表明，交联程度的增加会降低硅橡胶分子链运动中的能量损耗；由于预拉伸使得分子链上的极性基团活性降低，发生取向极化的概率减小，因此预拉伸程度越高、预拉伸持续时间越长，硅橡胶材料的介电常数越小，低频下的介电损耗越大。

Effect of prestretching on dielectric properties of silicone rubber

With liquid silicone rubber DC 186 as the matrix, different silicone rubber film materials were prepared by regulating the amount of cross-linking system. The effect of cross-linking degree on mechanical properties of silicone rubber materials and the effects of the prestretching degree and duration on dielectric properties of silicone rubber materials were studied. The results showed that the increase in cross-linking degree could reduce the energy loss in the movement of silicone rubber molecular chain. Because the prestretching reduced the activity of polar groups on the molecular chain and the probability of orientation polarization, the higher the prestretching degree and the longer the prestretching duration, the smaller the dielectric constant of silicone rubber material and the higher the dielectric loss at low frequency.