Electrical Properties Of Fe₃O₄/TPU Fiber Directional Modified Epoxy Resin

The orientation operation of the filler can significantly improve the application performance of the composite material in a specific direction.At present,the research on the directional modification of epoxy resin（Epoxy Resin,EP）is mainly focused on improving the thermal conductivity of composite materials,and the related research on electrical performance has not been fully developed.In order to explore the electrical properties of epoxy resin modified by magnetic fiber orientation,this paper uses electrospinning technology to prepare Fe₃O₄/TPU magnetic fiber,prepares fiber-oriented composite material with epoxy resin as the matrix,and studies the fiber orientation,diameter and length of the composite The thermal conductivity of materials and the influence of electrical properties.First,the Fe₃O₄/TPU fiber was analyzed by SEM and magnetic response test,and the arrangement of the fiber was studied.The results show that Fe₃O₄ is uniformly distributed on the fiber and the fiber has significant magnetic response characteristics;when the fiber length is 0.8mm-1.1 mm,the average deviation angle is 4.5°.Secondly,the thermal conductivity of the composite material was studied,and the results showed that the thermal conductivity of the composite material after fiber orientation filling in the parallel direction was about 2.01 times that of the unfilled epoxy under 7wt%filling amount;compared with the vertical direction,the thermal conductivity of epoxy resin in the fiber orientation direction increased by 0.825%,and the thermal conductivity of the composite material increased slightly with the increase of fiber diameter,but had no significant relationship with fiber length.Finally,the electrical properties of the composite material and its influencing factors were studied.The studies have shown that at a filling amount of 5wt%,compared with the vertical direction,the surface resistivity and flashover voltage of the 0.3mm diameter fiber filler material in the fiber orientation direction are reduced by 20.1%and 25.8%,respectively;0.2mm diameter fiber filled composite volume resistivity of flashover voltage,partial discharge starting voltage,breakdown field strength than 0.5mm fibrous filler were increased 44.2%,14.8%,9.4%,6.8%.The research in this paper shows that the Fe₃O₄/TPU fiber orientation filled with epoxy resin can make the thermal conductivity and surface electrical properties of the composite material present anisotropy,and the fiber diameter is the main factor affecting the electrical performance of the composite material.