A Green Approach for Recycling Compact Discs.

Compact discs (CDs) and digital versatile discs (DVDs) are mainly made by polycarbonate disc, a thin layer of aluminum or silver, a thin layer of a coating and a thin layer of a label of paper or PET. The recycling of these discs is difficult due to the removal of these non-polymeric layers and to our best knowledge, no industrial plants have been resent for their recycling. In this work, we propose a facile way to remove the non-polymeric layers and investigate the effect of the repetitive extrusion process on the processability and on the mechanical properties of the recycled polycarbonate. A few works have been published dealing with both the removal of the non-polymeric layers and the mechanical recycling of the disk of polycarbonate. In our approach, the removal of the non-polymeric layers is easily obtained through a thermo-mechanical treatment in a basic solution by ammonia. This process can be considered green because is made at a low temperature with a small amount of water and a very small amount of ammonia, saving energy and water. The properties of the polycarbonate remain good if the mechanical recycling is made after drying the post-consumer polycarbonate.