中文摘要：

为了进一步研究聚合物基复合材料的拉伸效应,采用简单的物理混合法制备了Ni/PVDF复合薄膜并在120℃下进行拉伸改性研究。结果表明：镍含量远低于渗流阈值的样品,通过拉伸实现了与渗流效应类似的介电常数剧增的拉伸渗流效应 在伸长倍数为2.3时介电常数急剧增大,最大增幅17倍（12→220）,同时电导率也增大了4-5个数量级,薄膜有绝缘体向导体转变的趋势。介电常数随拉伸倍数增加而大幅增加,是因为复合薄膜中的镍颗粒在外力拉伸作用下,其分布、微观结构逐步发生变化,以致形成了杆状镍颗粒群和微平行电容器结构等导电网络,发生拉伸渗流效应 同时,电导率的大幅增加也符合渗流理论的特征。

英文摘要：

In order to further understand the stretching effect of polymer-based composites,the Ni/PVDF films were prepared using a simple physics blending and then stretched at 120℃ to improve the electronic properties.The results show that there is an abrupt increase of 17 times（12→220） in the dielectric constant of the stretched samples at the stretching ratio of 2.3 with Ni content less than the percolation threshold,which is similar to percolation and named stretching-induced percolation.Additionally,an insulation-conduction transition tends to occur with enhancement of 4～5 orders of magnitude in conductivity after stretching.The enhancement in the dielectric constant with increase of stretching ratio is attributed to the gradual formation of conductive networks induced by stretching,which consists of a great many nickel groups and micro-parallel-capacitors.The large increase in conductivity is in agreement with the percolation theory before and after stretching.