Study On Interface And Dielectric Properties Of PVDF-Based Polymer Composites

The rapid development of modern electronic and electrical industry,the general function of the dielectric material is more and more unable to meet the application of new materials.A polymer-based ceramic composite material obtained by combining the flash points of ceramic materials and polymer materials has good processability and excellent dielectric properties,but there are still some practical problems to be solved urgently,such as filling capacity of nano-ceramic particles in the matrix,dispersion,compatibility with matrix interface.In order to study the effect of the filling amount of ceramic particles and the interface on the electrical properties of the composites,different structures of the core-shell structure were designed and the dielectric composites with high dielectric loss and high dielectric loss were successfully fabricated.First,barium titanate particles coated with PDA was used to fabricate core-shell BT@PDA-Ag nanoparticles,which were compounded with P(VDF-HFP)in different ratios to obtain composite film samples by solution casting.The method successfully applies the coulomb blocking effect of nano-Ag and the improvement effect of the PDA on the interface.The optimal values of the nano-particle filling amount of the core-shell structure in the polymer matrix and the dielectric properties of the composite material are mainly studied.The results show that the composites exhibit the best dielectric properties at 20%nanoparticle loading.Secondly,HBP and PDA were sequentially coated on the surface of the barium titanate particles to obtain BT @ HBP @ PDA nanoparticle with a core-shell structure embedded with nano-Ag.The composite materials with different interface structures were prepared by solution casting method with P(VDF-CTFE)in 20%loading.The relationship between different interface structures and dielectric energy storage of composites was studied.The results show that the double-shell HBP and PDA can effectively improve the interface compatibility between the nanoparticles and matrix,and obtain a high dielectric composite material.Finally,HIPS and BaTiO3(high dielectric constant)were used to study the best filling content and dielectric properties of composites.The results show that when the mass fraction of ceramic particles is 20%,the dielectric loss of the composite is significantly lower than that of the conventional fluorocopolymer.The filling amount of ceramic particles and the interface of the core-shell structure have a great influence on the dielectric properties of the composite materials.This study provides a reference for the application of composite materials in the dielectric field.