Preparation Of Boron Nitride And Its Thermal Conductivity Of Composite Materials

Thermally conductive materials have been widely used in industrial production and social life. However, the traditional thermally conductive materials have been difficult to adapt to the modern application. Now, the research and development of new thermally conductive materials have attracted more and more attention. It is a main preparation method for thermally conductive materials with filling thermal conductivity filler into polymer matrix. As a good thermal conductivity material, the preparation method and application of boron nitride has been widespread attention.First of all, boron nitride was prepared in this paper. Boron nitride (BN) material was successful prepared under the felling conditions:steel reactor, appropriate source material and suitable catalyst. X-ray diffraction, IR spectrum and scanning electron microscopy were used to analysis the property of boron nitride. The result indicated that the samples are crystalline and even appearance. Uniform layered structure was formed with nitrogen source of N2H4·2HC1and catalyst of Mg power, and the layered thickness is several tens to hundreds of nanometers.Secondly, this paper aims at investigating thermally conductive materials based on ethylene-vinyl acetate copolymer (EVA) and polythene (PE) with addition of BN as thermally conductive fillers. The factors such as dosage of fillerss、types of matrix and its ratio, and the composite structure, were discussed. The thermal conductivity and the tensile properties of thermally conductive composites were also taken into account. The results show that different thermally conductive fillers have different abilities to improve the thermal conductivity of composite materials. And the more filling, the more exaltation of thermal conductivity. When the filler of BN dosage is30wt.%, the thermal conductivity of the double-base composites increased. And there is a little effect with the adjunction of PE to the tensile properties of composites. When the filler of graphite dosage is30wt.%, the thermal conductivity of the double-base composites reduced with the adjunction of PE.