MELT BLENDING OF ULTRA-HIGH-MOLECULAR-WEIGHT AND HIGH-DENSITY POLYETHYLENE - THE EFFECT OF MIXING RATE ON THERMAL, MECHANICAL, AND MORPHOLOGICAL PROPERTIES

The blends of two different ultra high molecular weight polyethylenes (UHMWPE) and high density polyethylene (HDPE) were prepared in melt at different compositions and mixing rates in Brabender Torque Rheometer . The temperature build-up due to the internal friction during melt bl ending was recorded and evaluated with respect to the change in the to rque. The temperature at maximum torque was considered the fusion poin t temperature of the UHMWPE in the blend. This fusion point temperatur e was found to depend on the composition, mixing rate, and molecular w eight. The effect of mixing rate on the mechanical properties (measure d as yield and tensile strengths and elongation at break), thermal oxi dative degradation and melting behavior were studied. The morphology o f the blends were investigated by optical microscopy.