Chemical resistance evaluation of polystyrene / polypropylene blends : effect of blend compositions and SEBS comtent

摘要

The present study investigates the effect of styrene-b-(ethylene-co-butylenes)-udb-styrene (SEBS) and blend ratio on the chemical resistance of PS/PP blends. Usinguda Brabender PL2000 twin-screw extruder, blends of PS rich PS/PP (composition ranging ofud90–60 wt % PS) containing different amount of SEBS were prepared and injectionudmoulded to be evaluated for chemical resistance. The results showed that theudchemical resistance of PS to acetone and tetrahydrofuran (THF) increased with increasingudPP content. The chemical resistance of PS/PP blends increased with increasingudSEBS content at relatively lower PP content but decreased with increasing SEBS contentudat higher PP content. Dynamic mechanical analysis showed that 60/40/25 PS/PP/udSEBS blends had better miscibility than 60/40/5 PS/PP/SEBS blends. However better miscibilityuddid not result in enhanced chemical resistance since SEBS itself was effected byudthe chemicals