聚偏氟乙烯/钛酸钡高介电复合材料的制备与研究

Preparation and Study of PVDF/BaTiO_3 High Dielectric Composites

受功能梯度材料设计理念的启发,采用聚合物微纳层叠共挤装置,提出了交替多层介电复合材料的假设,设计了(聚偏氟乙烯/钛酸钡)(PVDF/BaTiO3)/PVDF交替多层介电复合材料,研究了复合材料的结构和性能。结果表明,复合材料中PVDF以α、β两种晶型共存;随着BaTiO3含量的增加,体系的结晶度逐渐降低;介电常数先增大后减小,在BaTiO3质量分数为7.5%时,介电常数达到最大61.43 F/m(25℃,1 MHz);介电损耗因数先减小后增大,但介电损耗因数都小于0.1。因此,利用微纳多层共挤技术,设计的交替多层介电复合材料满足要求。

This subject was inspired by the design concept of functionally graded materials; polymer micro-nano muhilayer coextrusion device was used; assumptions about the alternating multilayer dielectric composites were put forward; the structure and properties of composites were researched.The results showed the coexistence of α-and β-PVDF phases in the samples.With the increase of BaTiO 3 content,the degree of crystallinity of the composites were gradually reduced ; the dielectric constant first increased,then decreased,and reached at the maximum value 61.43 F/m （25℃,1 MHz） when BaTiO3 overall content was 7.5 wt％.The dielectric loss first reduced and then increased,but all the dielectric loss was less than 0.1.Therefore,the use of micro-nano multilayer coextrusion technology to design the alternating muhilayer dielectric composite met the requirements.