Morphology and Mechanical Properties Investigation of Binary Polymer Blends Based on PP/SEBS and PP/PC

Abstract

In this study, eight binary blends of polypropylene (PP)/ poly [styrene-b-(ethylene-co butylene)-b-styrene] tri-block copolymer (SEBS) and polypropylene (PP)/ polycarbonate (PC) were produced at different composition through twin screw extruder. The composition of the minor phases was changed to correlate the morphology and mechanical properties of binary blends (PP/PC and PP/SEBS) through thermal properties. To serve this purpose and to study the composition weight, composition weight ratio of SEBS and PC was change from 10% to 30% in PP/PC and PP/SEBS. With increasing SEBS wt%, toughness grows slightly and in 30wt% of SEBS reached to its maximum value, which uniform morphology created by PP/SEBS plays important role in this matter. On the other hand, with increasing PC wt%, tensile properties have upward trend, but size of holes, due to lack of proper adhesion between two polymeric surface, rose. The results of DCS have shown that SEBS cannot act as nucleation agents (heterogeneous nucleation) but the PC particles in this situation can act as nucleation agent in PP crystallinity. Increasing SEBS percentages leads to immobility of PP segments and hamper the crystallinity. PC particles in PP matrix are heterogeneous nucleation agent, which leads to increasing in crystallinity temperature compared to the pure PP.

Keywords

• morphology
• polypropylene
• mechanical properties