Interaction of mixing factors with mechanical properties of PP/ENR blend via response surface methodology / Noraiham Mohamad … [et al.]

This research is carried out to establish interaction between mixing parameters with mechanical properties of polypropylene (PP) incorporated with epoxidized natural rubber (ENR). The blends of PP/ENR were prepared by melt compounding using an internal mixer and vulcanized through sulfur curing system. The experiment was designed using two-level factorial design via response surface methodology by Design Expert software. Mechanical testing such as tensile test and impact test were performed to characterize the properties of PP/ENR blends. It was clearly observed that high ENR to PP ratio increases the toughness and flexibility of the PP/ENR blends. In comparison to the pure PP, PP/ENR blend with 40% ENR showed improvement of elongation at break and impact strength up to 68% and 56%, respectively. In contrary, the tensile strength and hardness decreases as the amount of PP decreases. The changes were associated to the properties imparted by the elastic chains of cross-linked ENR. The obtained properties showed good correlation with fracture surfaces observed in microscopy analysis performed by Field Emission Scanning Electron Microscope at magnifications of 500 and 5000-x.