Experimental Study Of The Thermal Conductivity Of Silicone Rubber Composite Materials Filled With MWNTS

With the coming of big data era, the requirements of science and technology for the highly integrated components are growing increasingly. This condition leads to the urgent need of the high-thermal conductivity materials, as a kind of high elastic material, people have already made many researches on the conductivity of silicon rubber.By using 107 silicon rubber as base gum, in this paper, we studied the effects of the addition of cross-linking agent(TEOS) and catalyst(DBTDL) on the conductivity of silicon rubber. It turned out that the cross-linking density and the conductivity reached the maximum when the addition amount of them was 3.6phr and 0.9phr respectively, and there is an obvious correspondence between the cross-linking density and the conductivity.In this paper, we studied the effect of the different solvent on the dispersion of MWNTs, and then prepared the MWNTs/107 silicon rubber composite materials. The study showed that isopropyl alcohol could disperse the MWNTs the best, and maximize the conductivity of the composite by using it as the solvent.To make a sufficient amount of Fe3O4 particles adhere to the surface of carbon nanotubes, evenly and firmly, we prepared the Fe3O4/MWNTs composite particles by solvothermal reaction. Firstly, We conducted the experiment about the MWNTs surface functionalization treatment, and secondly ? prepared the Fe3O4 particles that was adhered to MWNTs by solvothermal reaction. TEM results showed that after the functionalization treatment by using SDS, the dispersion of the MWNTs would be improved, and the treatment could make Fe3O4 particles adhere to MWNTs more firmly. The TGA result showed that the amount of Fe3O4 particles became more after using SDS; the amount and the size of the Fe3O4 particles were more perfect when the addition amount of Fe3+ was 0.002mol.We studied the MWNTs'effect on the conductivity of the 107 silicon rubber composite materials in this paper. When the addition amount of the MWNTs whose diameter is 60-100nm was 4phr, the MWNTs had obvious agglomeration that broke the thermal conductivity network, that is the reason why the conductivity of the composite declined. While as the addition amount grows, the thermal conductivity network make improvement, the conductivity increased again.In this paper, we studied the effect of oriented MWNTs on the composites' conductivity. Compared to the non-oriented MWNTs, it made more contribution to improve the conductivity ? And because of the improvement of MWNTs'dispersion in base gum, the aggregation effect had been decreased, and the conductivity kept rising with the growth of the addition amount of MWNTs without the falling phenomenon.