Conductive Polymer Embedded Three-dimensional Conductive Network Structure And Its Electrical Properties

With the rapid development of modern electronics and information industry,filled conductive composites as functional new materials have attracted the attention of researchers and entrepreneurs.Designing and manufacturing an effective network structure is the key to achieving the multi-functional development goals of conductive composite materials.However,the diversity and complexity of the conductive network structure increase the difficulty of compounding the conductive filler with the organic matrix,and new methods need to be introduced to promote its development.For this reason,this paper proposes a new method for preparation of conductive composites based on Selective Laser Sintering(SLS)with embedded honeycomb-like porous graphite skeletons to solve the technical difficulties of controllable construction of conductive composites with embedded3-D conductive networks and to obtain high performance graphite filled conductive composites.In this paper,the finite element method was used to simulate and analyze the effects of different honeycomb-like porous graphite framework conductive network structures and different basic feature cell sizes on the electrical properties of conductive composites.This result reveals the change law of its resistivity,establishes the resistivity calculation model,and provides a basis for designing a reasonable honeycomb-like porous graphite skeleton structure.The effects of different post-treatment processes on the electrical properties of the honeycombed porous graphite skeleton SLS prototypes were investigated.The study found that the carbonization treatment can significantly increase its electrical conductivity to 20.8S/cm.On the basis of the experimental study of two different densification methods,the optimal post-treatment process route for honeycomb-like porous graphite skeletons was determined.That is,the impregnation of two vacuum pressures with appropriate hightemperature carbonization can make its conductivity reach 42.8S/cm.In the experiment,the honeycomb-like porous graphite skeleton and the phenolic resin matrix were composited using a hot press forming process.The effects of different post-treatment processes,different honeycomb structures,and different cell densities on the electrical properties were also investigated and the foregoing resistivity calculation model was also verified.It was found that after the post-treatment of the porous graphite framework,the electrical properties of the conductive composites increased significantly.Compared with the Y-type honeycomb porous graphite framework structure,the conductive properties of the embedded parallel-type honeycomb porous graphite framework are better.Moreover,increasing the density of the honeycombs is good to improve the electrical properties of the conductive composites.The honeycomb-like porous graphite skeleton and the epoxy resin matrix were composited.Based on the comparative study of the effect of the curing agent on the curing effect and the effect of the curing temperature on the curing time,the curing agent and the curing temperature were determined.That is: the use of d230 polyetheramine cured for 1h at 100 °C can obtain the conductive composites of good quality.It is found that the conductive composite prepared by epoxy resin instead of phenolic resin has better flexural strength,but the electrical properties are comparable without changing the porous graphite skeleton.