Tribological properties of polyoxymethylene composites (part 3): comparison with polypropylene, high density polyethylene, and polycarbonate

摘要

In the previous paper, we showed that the specific wear rate of crystalline polymer, polyoxymethylene (POM), was drastically lowered by the addition of a trace amount of fine silicon carbide (SiC). The phenomena were ascribable to the decrease in the spherulite size of POM crystallites. In this paper, the filling effects of a trace amount of SiC or metal salt of dehydroabietic acid (M-DAA, a nucleating agent) on the tribological behaviors of polypropylene (PP), high density polyethylene (IIDPE), and polyvarbonate (PC) were investigated. The mechanical properties of PP and HDPE, both filled with SiC or MDAA, were also examined. As the results, the specific wear rates for filled-PP nd HDPE were minimized by the reduction in spherulite size. However the mechanical properties were not lowered by the addition of a trace amount of SiC or M-DAA. The specific wear rate for the amorphous PC was not affected by the addition of SiC. HDPE also showed the increment in izod impact strength with reduction in spherulite size. The effects were confirmed significant in the semi-crystalline polymers such as PP and HDPE, as well as POM. Therefore the reduction of spherulite size by the addition of SiC or M-DAA was effective for reducing the wear rate of semi-crystalline polymers without lowering the mechanical properties.