Preparation of oriented graphite/polymer composite sheets with high thermal conductivities by tape casting

Oriented graphite/polymer composite sheets were prepared using natural, crystalline flake graphites as raw materials, polyvinyl butyral as binders, polyethylene glycol and dibutyl phthalate as plasticizers by a tape-casting method at room temperature. The dependences of the binder contents and the blade heights on the orientation of the composite sheets were studied, and the effect of the orientation on the thermal conductivity was investigated. X-ray diffraction patterns and scanning electron microscope images showed that as-prepared samples showed different degrees of orientation. The thermal conductivity increased with the degree of orientation. The highest thermal conductivity of 490 W/m K could be achieved by optimizing the binder contents and the blade heights.