PU／ATH纳米复合材料的击穿和介电性能∗

摘要

用原位聚合的方法得到聚氨酯／氢氧化铝（ P U／ATH ）纳米复合材料，研究了ATH含量对P U／ATH纳米复合材料工频击穿场强、正负极性直流击穿场强、不同频率下的相对介电常数和介质损耗角正切值的影响。结果表明， P U／ATH纳米复合材料中ATH质量分数未超过3％时，随ATH含量增加，PU／ATH纳米复合材料的工频击穿场强、正负极性直流击穿场强增加， PU／ATH纳米复合材料的相对介电常数和介质损耗角正切值降低；ATH质量分数超过3％后，随ATH含量分数的增加，PU／ATH纳米复合材料的工频击穿场强、正负极性直流击穿场强开始降低，PU／ATH纳米复合材料的相对介电常数和介质损耗角正切值增加。 ATH改性的P U其相对介电常数和介质损耗角正切值高于纯PU的，且两者趋势相同。%Polyurethane( PU)/aluminum hydroxide( ATH) nano composites was prepared by in⁃situ polymeri⁃zation. The changes of frequency breakdown field strength, polarity DC breakdown field strength, relative dielectric constant and dielectric loss tangent of different frequencies of PU/ATH nano composites were studied with the con⁃tent of ATH. The results showed that, when the content of ATH was no more than 3%in PU/ATH nanometers com⁃posite, the frequency breakdown field strength, positive and negative polarity of the DC breakdown field strength were increased and the relative dielectric constant and dielectric loss tangent of PU/ATH nano composites were de⁃creased with ATH content increased. When the content of ATH was more than 3% in PU/ATH nanometers compos⁃ite, the frequency breakdown field strength, positive and negative polarity of the DC breakdown field strength were decreased and the relative dielectric constant and dielectric loss tangent of PU/ATH nano composites were increased with ATH content increased. Relative dielectric constant and dielectric loss tangent value of PU modified by ATH were higher than pure PU, and they had the same trend.