Ba_(0.6)Sr_(0.4)TiO_(3)/聚偏氟乙烯-聚甲基丙烯酸甲酯复合材料的制备及其介电性能

Fabrication and Dielectric Properties of Ba_(0.6)Sr_(0.4)TiO_(3)/Poly(vinylidene fluoride)⁃Poly(methyl methacrylate)Composites

采用流延热压工艺制备Ba_(0.6)Sr_(0.4)TiO_(3)(BST)/聚偏氟乙烯(PVDF)⁃聚甲基丙烯酸甲酯(PMMA)复合薄膜,研究了PMMA含量对复合材料微观组织结构和介电性能的影响规律。结果表明,BST相能够均匀分散在聚合物基体中,归因于PMMA与PVDF良好的相容性,2种聚合物之间的界面不分明;随着PMMA含量的增加,复合材料的介电常数先降低后升高,耐击穿强度和介电可调性先增加后减少。PMMA含量(体积分数)为15%的BST/PVDF⁃PMMA_(15)复合材料的综合性能最佳:介电常数为23.2,介电损耗为0.07,耐击穿强度为1412 kV·cm^(-1),在550 kV·cm^(-1)偏压场下,介电可调性为26.2%。

Ba_(0.6)Sr_(0.4)TiO_(3)(BST)/poly(vinylidene fluoride)(PVDF)⁃poly(methyl methacrylate)(PMMA)composite films were prepared by tape casting and hot pressing.The effects of PMMA content on the phase structure and electrical properties of the composites were studied.The results showed that the BST phase was uniformly dispersed in the polymer matrix.The interface between the two polymers is not clear,which is attributed to the good compatibility between PMMA and PVDF.With the increase of PMMA content,the dielectric constant of the composites is nega⁃tively correlated with the breakdown strength and dielectric tunability.BST/PVDF⁃PMMA_(15) composite with PMMA content(volume fraction)of 15%showed the best dielectric properties with the dielectric constant of 23.2,the dielectric loss of 0.07,the breakdown strength of 1412 kV·cm^(-1),and the dielectric tunability was 26.2%under the DC bias of 550 kV·cm^(-1).