The possibility of using a mixture of PET waste from mineral water bottles and a high rank bituminous coal as precursor for the production of carbon materials was studied. Taking into account the fact that a 10 wt% addition of PET waste totally changes the thermoplastic properties of coal, blends of coal and PET of up to 50 wt% were subjected to thermogravimetric analysis and carbonization at 800 degrees C. The chars produced were evaluated by optical microscopy and surface area measurements. The presence of PET waste promotes the formation of isotropic carbon and increases the microporosity of the chars obtained from the blends. For comparison purposes, the coal was oxidized at 200 degrees C for 24 h to avoid the fluid stage of the coal and afterwards carbonised in the same conditions. The causes of the effect of PET waste on the texture of the chars obtained from the blends are discussed. (c) 2004 Elsevier B.V. All rights reserved.