Preparation And Properties Investigation Of Multi-Dimensional Fillers/PVDF Composites

With a single filler,it's difficult to meet the performance requirements for polymerbased composite dielectric materials.A viable strategy for developing composite dielectric materials with superior overall properties is to combine multiple fillers with structural design.The goal of this paper is to design and prepare polyaniline(PANI)-coated barium titanate(BT)core-shell particles,which are then blended with graphene oxide(GO)and hexagonal boron nitride(h BN)microplatelets to create multidimensional hybrid fillers.The structure and morphology of the three fillers and composites are characterized,and the effects of filler type and content on composite properties are investigated and analyzed.Emulsion polymer was used to make PANI@BT particles with a core-shell structure,and the crystal form of BT particles was not affected.The addition of GO to PANI@BT particles improves particle dispersion.PANI@BT-GO/PVDF composites have significantly improved mechanical,thermal,and dielectric properties when compared to PANI@BT/PVDF composites.PANI@BT-GO/PVDF has the highest tensile strength and elongation at break,with 41.74 MPa and 15.52%,respectively.The temperature of 20%thermal weight loss in 50% PANI@BT-GO/PVDF composite is 398.28 °C,which is 11.9%higher than that of PANI@BT/PVDF composite;its dielectric constant is the largest,reaching 124.85 at 100 Hz,which is higher than 50%.PANI@BT/PVDF increased by44.6%,compared to pure PVDF,which increased by 117.4%.With the addition of filler,the composite material's conductivity and dielectric loss increased slightly,but the insulating nature was always maintained,and the breakdown field strength decreased.It demonstrates that the addition of GO improves the dispersion of fillers,and that its own properties contribute to the improvement of the composites' overall properties.The h BN sheets were effectively peeled off and had hydroxyl groups after calcination and ultrasonic treatment,and the addition of h BN could significantly improve the dispersion of PANI@BT particles in the polymer matrix.PANI@BT-h BN/PVDF outperforms PANI@BT/PVDF and PANI@BT-GO/PVDF in terms of mechanical properties,thermal stability,and dielectric properties.The maximum elongation at break of the 20% PANI@BT-h BN/PVDF composite is 23.97%,which is 1.25 and 4.15 times that of pure PVDF and 20% PANI@BT/PVDF composite,respectively,indicating good toughness.At 100 Hz,the dielectric constant of 50% PANI@BT-h BN/PVDF is 169.46,which is 103.3% higher than that of 50% PANI@BT/PVDF composite and 162.9% higher than that of pure PVDF.Despite the fact that the loss has increased,the insulating nature of the material has remained constant.The breakdown field strength of 10% PANI@BTh BN/PVDF composites is the highest,reaching 145.2 k V/mm,which is 6.6% higher than pure PVDF,and then gradually decreases,but remains higher than PANI@BT/PVDF and PANI@BT-GO/PVDF composites.It demonstrates that h BN can significantly improve the dispersibility of PANI@BT,and that its own properties can help composites improve their heat resistance and breakdown field strength.