聚偏二氟乙烯/炭黑复合膜的制备与介电性能

Preparation and Dielectric Properties of PVDF-carbon Composite Films

添加高介电陶瓷粒子来提高复合材料的介电常数常因高含量陶瓷粒子影响复合材料的力学性能。本文将炭黑粒子引入到聚偏二氟乙烯(PVDF)中来降低陶瓷粒子的用量,通过固相混合法将PVDF和炭黑粒子混合后热压制备两相高介电复合材料。利用傅立叶红外光谱、X射线衍射、差示扫描量热仪、热重分析、动态力学分析仪和宽频介电谱阻抗分析仪等手段对复合材料的结构和性能进行分析发现。炭黑粒子均匀地分散在PVDF基体中,并存在一定的化学键作用。复合材料的力学性能随着炭黑粒子的升高而降低很小,当炭黑含量为3%时,介电常数最高达到19。

Traditional polymer composite preparation techniques often employ much ceramic particles with high dielectric constants, which can damage the mechanical properties. Classic nanocomposites with polyvinylidene fluoride (PVDF ) polymer matrices, BaTiO3 nanoparticle (BTP ) fillers and carbon were created by a clean method combining planetary ball milling with an ultracentrifugal mill and then hot pressed into thin films. The microstructures and properties of thin films were characterized and analyzed. Scanning electron microscopy (SEM ) results demonstrated that BTP and carbon was homogeneously dispersed in the PVDF matrix. The thermal, mechanical and dielectric properties were comparable to those of composite films prepared by solution mixing. Dielectric analysis revealed that the dielectric constant of the thin films reached 19 (10^4 Hz ) when the volume fraction of carbon was 3%.