Study on the effect of processing conditions on the mechanical properties of PP/PC/SEBS ternary blends using Taguchi experimental analysis

Abstract

AbstractIn this study, nine ternary polymer blends based on polypropylene (PP)/polycarbonate (PC)/styrene-ethylene-butylene-styrene triblock copolymer (SEBS) with the same compositions (70%wt PP, 15%wt PC, 7.5%wt SEBS and 7.5%wt maleic-anhydride grafted SEBS (SEBS-g-MAH) as a compatibilizer) are prepared using twin screw extruder at different levels of die temperature (235-245- 255 °C), screw speed (70-100-130rpm) and blending sequence (M1-M2-M3) . In M1 procedure, all of the components are dry blended and extruded simultaneously using Brabender twin-screw extruder. In M2 procedure, PC, SEBS, and SEBS-g- MAH minor phases are first pre-blended in twin screw extruder and after granulating are added to PP continuous phase in twin screw extruder. Consequently, in M3 procedure, PP and SEBS-g-MAH are first pre-blended and then are extruded with other components. The influence of these parameters as processing conditions on mechanical properties of PP/PC/SEBS ternary blends is investigated using L9 Taghuchi experimental design. The responding variables are impact strength and tensile properties (young modulus and yield stress) which are influenced by the morphology of ternary blend and the results are used to perform the analysis of variance (ANOVA). It is shown that the resulted morphology, tensile and impact strength are influenced by extrusion variables. Additionally the optimum processing conditions of ternary PP/PC/SEBS blends from Taguchi analysis was achieved.