Measurement of thermal conductivity of hollow glass-bead-filled polypropylene composites

Thermal conductivity is an important heat transfer property of materials but the heat transfer process is very complicated for polymer composites. The effective thermal conductivity (keff) of hollow glass-bead (HGB)-filled polypropylene (PP) composites was measured by means of a thermal conductivity instrument to identify the effects of the content and size of HGBs on the effective thermal conductivity for these filled systems. The results showed that the measured keff decreased roughly linearly with increase of the volume fraction (φf) of HGB. In addition, keff decreased slightly with increase of the particle diameter when φf was constant.