Sudy on the Polypropylene/High Density Polyethylene/Styrene-Butadiene-Styrene Block Copolymer Ternary Blends II. The Effect of Processing on the Properties and Morphology of Polypropylene/High Density Polyethylene/ StyreneButadiene-Styrene Ternary Blends

Abstract

It has been shown that the impact strength of non-compatible polymer blends is closely related to the number, shape and morphology of the dispersed phase particles. The general condition for toughening is that the inter-particle distance must be smaller than a critical value T. (Critical Inter-Particle Distance). Thus a sharp brittleductile transition mould occur as T becomes smaller than T. This has been applied to interpret the relationships of the impact strength of the blends with their respective phase morphology, particle diameter and elastomer volume fraction. The objective of this study is to examine the effect of various blending processes on the morphology of the rubber particles in the PP/HDPE/SBS ternary blends. The relation of the impact strength of PP ternary blends with the SBS particle diameter has been investigated. It is found that the morphology of the SBS dispersed phase particles is closely related to the mechanical properties of the PP ternary blends and it is very much depen dent upon the processing parameters of the blends.