The use of recycled printed circuit boards as reinforcing fillers in the polyester composite

The feasibility of using recycled printed circuit boards (PCB) as reinforcing fillers in manufacturing unsaturated polyester (UP) composites was studied using differential scanning calorimetry (DSC), and mechanical test. The concentrations of Cu leached from the molded products were also tested. From the DSC measurement, it was obtained that the addition of PCB affected the free radical reaction of the UP resin and decreased curing rates at the beginning stage. The methods of surface treatments also affected the curing kinetics of the UP resin. PCB modified UP resins had higher Tg, and were tougher and stronger than the plain UP because of energy dissipation effects from glass fibers and rigid epoxy resins in the PCB. The impact energy of the specimen increased with increasing the loading of PCB fillers. The size of PCB fillers and the type of surface treatments affected the mechanical properties and the concentrations of copper leached from molded products. As much as 150 parts per hundred PCB could be added in the UP without violating the environmental regulation. However, the addition of PCB darkened the appearance of the molded specimen. Production of UP composites from waste PCB was justified.