Influence of Morphology on Mechanical Properties under the Combined Use of SEBS and EOr as Elastomer in PP/Elastomer/Filler Ternary Composites

Abstract

The influences of combined elastomers on impact properties and morphology of polypropylene (PP)/elastomer/CaCO₃ ternary composites were investigated. In the case that polystyrene-block-poly(ethylene-butene)-block-polystyrene triblock copolymer (SEBS) and poly(ethylene-co-octene) (EOR) were used as elastomers, a sea-island structure consisting of EOR dispersed phase and SEBS continuous phase was formed. The elastomer and the CaCO₃ particles were separately dispersed in PP matrix. In the case that carboxylated SEBS (C-SEBS) and EOR were used, the C-SEBS particles were dispersed in the EOR particles. Almost all of the CaCO₃ particles were dispersed in the PP matrix, although some of the CaCO₃ particles were dispersed in the C-SEBS/EOR combined particles. Impact strength improved with an increase of incorporated CaCO₃ particles. The effect of elastomer on the impact strength was SEBS ≥ SEBS/EOR > EOR = C-SEBS/EOR > C-SEBS. The morphology formed by elastomer and CaCO₃ particles strongly affected the impact properties of the ternary composites.