聚四氟乙烯多孔膜的压电活性及其稳定性

Piezoelectric activity and its stability of polytetrafluoroethylene(PTFE)films

研究了经单向机械拉伸形成的非极性空间电荷型薄膜驻极体聚四氟乙烯 (PTFE)多孔膜的压电性 .讨论了由PTFE多孔膜和非多孔的聚合物薄膜 (PTFE ,聚酰亚胺PI,氟化乙丙烯共聚物FEP和聚三氟氯乙烯PCTFE)组成的双层膜的突出压电活性 .初步研究结果指出 :在优化的极化条件下形成的上述双层压电膜以外电极测量的准静态压电d33常数可达 186pC N ,这个数值与压电陶瓷锆钛酸铅PZT的相应常数接近 ,而比铁电聚合物聚偏氟乙烯 (PVDF)的相应常数约高出一个数量级 .还研究了这类柔性多孔膜压电性的突出的热稳定性 ,考察了充电参数如充电时间、充电温度和电晕电场等及储存的电荷密度对这类双层膜的压电活性的影响 .充电参数对压电性的影响还借助于电荷动力学规律和材料性质进行了解释 .

Piezoelectricity of non-polar space charge electret, porous PTFE film with unidirectional mechanical stretch was studied. Piezoelectricity of double-layer stacks of porous PTFE and non - porous polymer films (such as PTFE, PI, FEP and PCTFE) with space charge layer were investigated. The results of preliminary investigation pointed out that under the optimal poling conditions, piezoelectric coefficient d(33) of porous PTFE with external electrode was up to 186 pC/N which is close to the value of ferroelectric ceramics PZT, and was about one order of magnitude that of ferroelectric polymer PVDF. Outstanding thermal stability of piezoelectricity for soft PTFE porous film was reported. Influences of poling parameters such as poling time, corona electrical field and charging temperature etc, as well as charge density stored in the material on piezoelectricity were investigated. The influences of charging parameters on piezoelectricity were also explained by means of charge dynamic character and the material property.