Study On Preparation And Dielectric Properties Of PVDF-ceramic-carbon

PVDF, one of the ferroelectric organic polymer materials, is the most widelyused currently. As a kind of new functional composite materials, PVDF/ferroelectricceramic composites not only overcome the defect of polymeric materials and theferroelectric ceramics, but also improve other properties of the composites. It have theadvantages such as high flexibility and easy processing，so it has potential applicationprospects especially in military, medical and electronics industries‘With thedevelopment of social productive ofrces，the PVDF/ceramic composites are demandedto possess better performance，especially dielectirc properties. Therefore, it isimpotrant to improve the combination property of the composites.But it is unsustainable to increase the dielectric properties of composites with asingle ceramic powders mixed in PVDF. Instead，with the increment of ceramicpowder doped, it will not only fail to improve the dielectric properties of thecomposites, but also does great damage to the good physical properties such aslfexibility, tensile strength. So on the basis of the single ceramic powder, then thisexperiment add another kind of carbon materials in PVDF. At last the carbonmaterials improve the dielectric properties of the composites effectively.This study used PVDF as the matrix mateiral, barium titanate (BaTiC>3，BT),barium strontium titanate (Bao65Sro0.35Ti3, BST) as ceramic powders, multi-walledcarbon nanotube (MWCNT), graphene oxide (GO) as the carbon materials. PVDF-BT,PVDF-15%BT-MWCNT, PVDF-15%BST-MWCNT, PVDF-15%BT-GO compositeswere prepared by solution blending-casting method. And the different content of ceramic powder and carbon materials of composites on the dielectric properties werealso studied, the mechanism of the experiment has been discussed systematically. Inthis study, ceramic powder, carbon mateirals and the microstructure of the compositeswere characterized by Scanning electron microscope (SEM), Field emission scanningelectron microscope (FE-SEM), X ray diffraction (XRD), Fourier infrared spectrum(FT-IR), Raman spectroscopy (Raman).Different content of ceramic powder and carbon materials were worked toexplore the connection between macro properties and microstructure of thecomposites in this experiment. Experimental results show that when the BT powdercontent is15%，PVDF-BT composite shows the best dielectric properties relativedielectric constant is12.41，dielectric loss was2.268%，but there are still many holesin the material, it still has the obvious lfaw. With adding MWCNT in PVDF-15%BT，when the MWCNT content is5.8%, the maximum relative dielectric constant is31.27,at the time the dielectric loss is3.302%. To explore the internal relations among BT,MWCNT,PVDF, the PVDF-15%BST-5.5%MWCNT weer prepared. With addingGO in PVDF-15%BT,when the GO content is2%, the relative dielectric constant is20.47，dielectric loss is5.127%.