Mechanical properties of PP matrix composites filled with nonmetals recycled from waste PCB and milled glass fibers

Polypropylene (PP) matrix composites，reinforced with nonmetals recycled from waste printed circuit boards and milled glass fibers，respectively，were prepared by the melt blending method. The effects of the two reinforcing materials and surface modification on the strengthening of PP matrix were investigated based on the results of mechanical properties and impact fracture surface morphologies of the composites，and on the surface morphologies of the two reinforcing materials. The results show that both strength and rigidity of the composites can be successfully reinforced by filling the two materials. The maximum increment of tensile strength，tensile modulus，flexural st rength and flexural modulus of the nonmetals/PP composites is 28%，41%，86% and 133%，respectively，but the toughness decreases. The surface modification of nonmetals has little effect on the mechanical properties of the composites，while the surface modification of the milled glass fibers has a great effect. The nonmetals recycled are more effective in improving the mechanical properties of the composites than the milled glass fibers，and can replace milled glass fibers as reinforcing fillers in the PP composites，which provides a promising way for resolving the environmental pollutions，recycling resources and reducing the composite materials cost.