Study On Preparation And Dielectric Property Of Fe₃ O₄ /MWCNTs/PVDF Composites

With the two or more material compound,special performance composites are prepared by playing the advantage of each component materials, high dielectric constant polymer matrix composite materials have a significant applications. Although traditional ceramic dielectric material is very excellent dielectric properties, ceramic capacitor need high temperature firing, energy consumption, process complex in manufacturing process, and this kind of material have less flexible, these shortcomings affect its application. Therefore, the development of composite materials with high dielectric properties and good processing performance, especially polymer matrix composites, become research hot spot in recent years.Three-phase Fe₃O₄/MWCNTs/PVDF composites prepared by using a melt blending and hot-molding technique, mass rate of MWCNTs and /Fe₃O₄ is 1:1, the total of MWCNTs and Fe₃O₄ is 0, 0.5%,1.0%,1.5%,2.0%,2.5%,3.0%,3.5% respective. The dependence of the dielectric constant on frequency, presser temperature and the mass ratio of MWCNTs and Fe₃O₄ particles are investigated. The results indicated that the dielectric constant of the composites can increase by adding suitable quantity of Fe₃O₄/MWCNTs. when the total of MWCNTs and Fe₃O₄ is 2.5%, dielectric constant of MWCNTs/Fe₃O₄/PVDF composites is up to 35525 at 210℃hot-press and 103Hz; when the total of MWCNTs and Fe₃O₄ is 3.0%, dielectric constant of Fe₃O₄/MWCNTs/PVDF composites is up to 48946 at 230℃hot-press and 103Hz. The composites showed a high dielectric constant and high dielectric loss, showing potential application in microwave absorption materials.