The heat capacity and the thermal conductivity of composites prepared from PET and LDPE containing aluminium particles dispersed in the polyolefin matrix, both obtained from recycled packaging, were measured in the temperature range from 20 to 100 degreesC using modulated DSC. The heat capacity of composites decreases with the increase of PET content and the thermal conductivity showed a very complex dependence on composition, attributed to morphological effects. (C) 2004 Elsevier Ltd. All rights reserved.236637643