Research On The Influence Of Interfacial Treatment On The Thermal Conductive Properties Of Materials

With the rapid development of science and technology, traditional thermal conductive materials never meet modern industrial production. Thermal conductive polymer matrix materials show many advantages, such as high thermal conductivity, good physical and chemical performance and low cost for preparation. Enhancing thermal conductivity of polymer matrix materials has become a key point in research due to the low thermal conductivity of polymer. Three methods are usually used to improve the thermal conductivity of thermal conductive polymer matrix materials-enhancing thermal conductivity of polymer, using fillers with high thermal conductivity in polymer matrix, improving the interfacial condition of matrix and fillers.The main idea of this paper is focusing on improving the interfacial condition of polymer matrix and fillers. Two methods are used to fulfill this goal. The first one is using coupling agent to change the lipophilic property of the fillers to increase the compatibility of fillers and polymer matrix. Three coupling agents are used, KH-550, KH-560 and KH-570, and the influence of the p H of the treatment solution, the amount of the coupling agent and the time of the hydrolytic action are researched. When the p H is 5, the amount is 1.5% of the weight of the filler and the hydrolytic action time is 2h, the wetting angle of filler and water increases obviously. The thermal conductive properties of the thermal material filled by the treated fillers improves the most. Compared with the other two agents, the treatment by KH-560 increases the compatibility and thermal conductivity the most.The second way is by using sol-gel method to encompass fillers by Zn O to make core-shell structure. In the paper the coating concentration and the calcination temperature are studied. When the coating concentration is 1:5, the calcination temperature is 800 oC, Zn O entirely coats the surface of fillers, improving the wetting angle of fillers and epoxy resin and increasing the thermal conductivity of composite materials. Although the presence of Zn O would improve the compatibility of fillers and polymer matrix, the key point of the increasing thermal conductivity is introducing component with higher thermal conductivity.Moreover, several ways are used to test the properties of thermal composite materials like XRD, CTE, DMA, thermal conductivity, et al. The lattice distortion of fillers, the decrease of CTE, the increase of storage and loss modulus of composite materials are all influenced by the improving interfacial condition of fillers and polymer matrix. The thermal conductive properties of composite materials show that a limited effect is introduced treated by coupling agent. While with the amount of fillers used in the material aggrandizes, the thermal conductivity of the material merges a rapid increase since a larger amount of higher thermal conductivity component are contained in the material.