Anisotropic thermal properties of molded carbon phenolic spheres

Anisotropic thermal properties of molded carbon phenolic spheres (CPS), a m ixture of sugi wood charcoal powders and phenol formaldehyde resin molded w ith a hot press, were investigated. The effects of the carbonizing temperat ure, particle size of chars, and density of the CPS on thermal properties w ere discussed. The molded CPS specimens were measured for their thermal pro perties using the laser flash method in both horizontal and vertical direct ions. The configuration of the CPS was observed by scanning electron micros copy. Anisotropy of the thermal properties (thermal diffusivity and thermal conductivity) between horizontal and vertical directions of the molded CPS was much higher than that of the uncarbonized molded phenolic spheres. The refore, converting wood into molded CPS is an effective way to enhance the thermal-anisotropy properties. More marked effects of the carbonizing tempe rature, particle size, and density were observed in the horizontal directio n than in the vertical direction. Anisotropy in thermal properties of the m olded CPS may be considered an advantage for developing a new fire-retardan t material for wood composites.