组分对PI/TiO_2纳米复合薄膜电学性能的影响

采用原位聚合法制备聚酰亚胺/二氧化钛(PI/TiO2)纳米复合薄膜.利用扫描电镜、X射线衍射仪对复合薄膜进行表征及结构分析,研究无机组分对复合薄膜电学性能的影响.结果表明,TiO2颗粒与PI基体相容性好、分布较均匀.随着无机组分的增加(0~7%),复合薄膜的击穿场强先升高后降低,在1%组分处达到最大值240 kV/mm;复合薄膜的耐电晕寿命持续增加;介电常数先降低后升高,在3%组分处达到最小值3.11,在7%组分处为3.49;电导率与介电损耗随组分变化不大,在102Hz频率下,薄膜电导率均小于6.0×1013S/cm;聚酰亚胺/二氧化钛纳米复合薄膜具有良好的介电性能与热稳定性.

Effect of Content on the Electrical Properties of PI/nano-TiO2 Composite Films

Abstract：Polyimide/nano-TiO2 （PI/TiO2 ） composite films were prepared via in-situ dispersive polymeriza- tion. The cross section surface morphology and composition of fihns were analyzed by SEM and XRD. The purpose in this paper is to research the effect of content on the electrical properties of PI/TiO2 composite films by electrical measure. The results show that inorganic TiOz particles are homogeneously dispersed in the polymer matrices. With the TiO2 doping concentration increasing, breakdown voltage whose maximum is 240 kV/mm at 1% increases first and then decreases; time-to-breakdown of the composite films can be lengthened continuously; dielectric constant whose minimum and maximum are 3.11 （ at 3% ） and 3.49 （ at 7% ） decreases first and then increases. Conductivi- ty and dielectric loss nearly show no change after doping. In the frequency of 102 Hz, the conductivities of compos- ite films are lower than properties of polyimide, 6.0 x 1013S/cm. Nano-TiO2 doped composite films not only maintain excellent dielectric but also possess outstanding heat stability.