MECHANICAL AND MORPHOLOGICAL BEHAVIOR OF STATICALLY VULCANIZED PP/SBS BLEND WITH PEROXIDE

Considerable work has been carried out to improve the poor impact strength of polypropylene (PP) by the incorporation of elastomers such as ethylene-propylene diene rubber (EPDM), and styrene-butadiene block copolymer (SBS) [1-3]. There are many ways to combine the desired features of each component of the blend. Ichazo et al [4] studied the influence of vulcanization agents (sulphur and peroxide) on the rheological behavior of PP/SBS blends (90/10), where the rubber phase was statically cured. In this paper, the mechanical and morphological behavior of statically vulcanized PP/SBS 90/10 blends with peroxide is studied. Isotactic Polypropylene (PP) J-600 having a melt-flow index (MFI) of 7 g/10 min and Styrene-Butadiene-Styrene copolymer (SBS) with a density of 0.94 g/cm3 and a melt flow index of 0.5 g/10 min and a styrene content of 30 % were used. Curing agent for rubber was dicumyl peroxide (DCP). Blending of rubber with DCP was done in a Farrel two roll mill. Curing times chosen for this study correspond to intermediate points, above scorch time, within SBS curing curves; these curves were done in a Zwick oscillating disk rheometer at 160 °C. Vulcanized rubber sheets of SBS were prepared in a Carver hydraulic press at a temperature of 160 °C, then these sheets were cut and granulated with the intention of obtainin