Study on Polypropylene Matrix Composites Filled with Glass Fiber Recycled from Waste Printed Circuit Board

At the first stage of this work, waste printed circuit board was pyrolyzed under vacuum in a self-made batch pilot scale fixed bed reactor, and the glass fiber (GF) was separated from the pyrolysis residues by gravity method and purified by calcination in the air. Then, the GF/polypropylene (PP) composites was prepared by means of injection molding. The influence of GF particle size, mass fraction and surface pretreatment on the properties of composites was researched respectively. The results have shown that the GF of 0.45mm pretreated by silane coupling agents can effectively improve the characteristics of GF/PP composites. The mechanical and thermal properties were increased in the range of up to 30%GF and decreased with further increase in GF dosage. The optimum properties of GF/PP composites can be obtained at the GF content of 30%. Compared to pure PP, the increment of flexural modulus, flexural strength, tensile strength and impact strength is 68.42%, 31.16%, 25.93% and 41.38%, respectively. And the Vicat softening temperature (VST) is increased by 3.2°C.