Mechanical, thermal, morphological and leaching properties of nonmetallic printed circuit board waste in recycled HDPE composites

The nonmetallic powder recycled from waste printed circuit boards (PCBs) is used as a filler material in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. This study aims to propose methods for reuse of waste nonmetallic PCBs in a more environmentally friendly way. Mechanical, morphological, thermal and leaching characteristic properties of compatibilized and uncompatibilized composites were assessed. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt%, PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatibilizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites. While, overall thermal properties of the compatibilized and uncompatibilized rHDPE composites were low, which can be attributed to incorporation of nonmetallic PCB fillers in rHDPE possessing low thermal conductivity. In terms of environmental, after nonmetallic PCB was filled in rHDPE composites, the concentrations of Cu and Br in the leachates were far below the regulatory limits which are only 3.07 mg/L and 3.50 mg/L, respectively. So, it can be recommended that a balance in mechanical and thermal properties of composites without violating the environmental regulation was achieved with the incorporation of 30 wt% PCB and 6 phr MAPE compatibilizer. (C) 2013 Elsevier Ltd. All rights reserved.