Polymer modified graphene/polyvinylidene fluoride high-dielectric composite material and preparation method thereof

Abstract

The invention discloses a polymer modified graphene / polyvinylidene fluoride high-dielectric composite material and a preparation method thereof. The composite material is prepared by taking polyvinylidene fluoride as a matrix and taking graphene subjected to graft modification by aminosilane and polymer sequentially as dielectric enhancement functional filler through solution blending, electrostatic spinning and laminar hot-press molding sequentially. On the basis of dual regulation of interface and spatial microstructures, uniform dispersion of high-filling-volume graphene filler in the polyvinylidene fluoride matrix is effectively realized according to a graphene surface polymer grafting modification and electrostatic spinning combined method, and the dielectric constant of the obtainedgraphene / polyvinylidene fluoride composite material is evidently increased while a small dielectric dissipation factor is achieved, so that the polymer modified graphene / polyvinylidene fluoride high-dielectric composite material is applicable to fields of embedded capacitors, high-energy-density energy accumulators and the like.

Description

technical field [0001] The invention belongs to the technical field of composite materials, in particular to a polymer-modified graphene / polyvinylidene fluoride high-dielectric composite material and a preparation method thereof. Background technique [0002] Although polymer materials have excellent mechanical properties, chemical stability and electrical insulation, their dielectric constant is low, generally below 10, which greatly limits their application range. In recent years, researchers have discovered that conductive filler / polymer composites with high dielectric constants can be obtained by adding conductive fillers to polymers. According to the percolation theory, when the content of conductive fillers is very close to the percolation threshold but not enough to form a conductive network, the conductive fillers are very close but still separated from each other, which is equivalent to introducing a large number of microcapacitor structures into the polymer matrix....

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Problems solved by technology

Although the system shows good dielectric properties, there is still a lot of room for improvement

And the Chinese invention patent ("A polyvinylidene fluoride / graphene composite material and its preparation method", Xue Linxin, Liu Fu, Lin Haibo, Shen Jianhui, Xiang Yanhui, application number 201310372686.2) prepared graphene by melt blending method / polyvinylidene fluoride composite material, when the graphene content is 3wt.%, although the dielectric constant of the composite material can reach 100 at 1000Hz, the dielectric loss factor at 1000Hz is as high as 3000, so it is difficult to meet the practical application requirements

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