Morphology development of polypropylene elastomer blends From compounding to injection moulding

摘要

Model compounds of a polypropylene homopolymer with high and low molecular weight ethylene-octene copolymers (EOC) were melt blended. The blends were compounded at different processing conditions altering the shear rate, specific energy input, and residence time in the extruder. The morphology of the samples taken at different locations along the screw channel and from injection moulded tensile specimens was studied bySEM. It was found that the morphology evolution depends largely upon the processing conditions, time spent in mixing and formulation. Elastomer particle coalescence and break up phenomena compete with each other in defining the final blend morphology and properties of the blends.