Thermal Conductivity Study On Epoxy Resin Based Composites

With the rapid development of science and technology, higher thermal conductivity of traditional polymer materials is required in some special occasion. Among thermoset resins epoxy resin is one of the most popular matrix materials. And it owns good mechanical performance and is easy to manufacture, so it is very important to develop its thermal conductivity or composites' thermal conductivity.In this paper, gel-board method was adopted to test gel time of epoxy resin with different contents of curing agent. The influencing factors were discussed. The DSC method was adopted to analyze the heat flow of resin. Then, the activation energy was figured out respectively by Kissinger method and Flory method: 65.4kJ/mol and 65.80kJ/mol. The resin curing reaction order was figured out by Kissinger method: 1.86. The processing of curing is 70°C/lhour, 80°C/4hour, then cooling in mould or oven.In addition, new thermal conductivity testing equipment was developed by means of non-steady state method in order to provide convenience for research. Based on this, epoxy/thermal conductive filler composites are prepared and a series of thermal experiments were performed. The results indicated that thermal conductivity of composites increased with the increasing of filler content, and a sharp increase occurred. At the same filler content, thermal conductive property sequence was carborundum/epoxy>graphite/epoxy>alumina/epoxy, heat transfer network model was adopted to discuss the phenomenon.Creatively, thermal conductive fillers were filled in the fiber cloth reinforced polymer based composites in this paper, and then thermal conductive property was analyzed. The result indicated that thermal conductivity of composites increased with the increasing of filler content;however, sharp increase did not occurred in the range of filler contents. The filler is crystal structure, thus its heat is transfer by photon;heat transfer is quick. The epoxy matrix is non-crystal structure, thus its heat is transfer by means of vibration of atoms in material;heat transfer is slow. In the range of filler contents, filler is wrapped by matrix, so thermal conductive property has close relationship with matrix and heat transfer is comparatively slow.Meanwhile, a series of mechanical performance tests were performed for the casting products and fiber reinforced composites. The results indicated thatmechanical properties decreased with the increasing of filler content. The filler destroyed the consistency of material, the combination of filler and resin was not good and the interface between resin and filler was also destroyed.