Abstrato

Thermal investigation of phase change materials based on LLDPE, paraffin wax and expanded graphite

Mustapha Karkri

Abstract Paraffin waxes which are saturated hydrocarbon mixtures, generally entailing of a mixture of different alkanes are frequently used as phase change materials (PCMs) due to their numerous advantages such as high latent heat of fusion, negligible super-cooling, low vapour pressure in the melt and chemical inertness. Paraffin waxes, blended with appropriate polymers to avoid the leaching of paraffin during heating, seem to be the best way for preparation of smart PCMs for different applications such as thermal storage of solar energy, thermal protection of electronic devices, thermal protection of food and medical goods, passive storage in bioclimatic buildings and thermal comfort in vehicles.  Due to the relatively low thermal conductivity of LLPDE and also paraffin  wax  (approximately  0.2  W/m.K)  it  is  necessary  to  improve the thermal conductivity of the PCMs by adding conductive fillers. Nowadays, expanded graphite (EG) is commonly used to improve mechanical, electrical conductivity, thermal conductivity and other thermophysical properties.