Effects of accelerated aging and compatibilizers on the mechanical and morphological properties of polypropylene and poly(acrylonitrile-butadiene- styrene) blends

The effects of maleic anhydride-grafted styrene-ethylene-butylene-styrene copolymer (SEBS-g-MAH) on the mechanical and morphological properties of polypropylene (PP) and poly(acrylonitrile-butadiene-styrene) (ABS) blends were investigated. Based on mechanical properties, including impact and tensile strengths, the PP/ABS (70/30) blends containing SEBS-g-MAH showed improved impact strength with minimal loss of tensile strength. As determined from morphological studies of the PP/ABS blends, addition of SEBS-g-MAH decreased PP/ABS blend droplet size more than the addition of SEBS. Additionally, the effects of SEBS-g-MAH and SEBS on the mechanical and morphological properties of the PP/ABS (70/30) blends were investigated during accelerated aging in an oven at 90°C for 72 h (one cycle). The impact strength of the PP/ABS (70/30) blends with SEBS-g-MAH (7 phr) decreased less than 10% after five cycles, but blends with SEBS (7 phr) and blends without compatibilizer decreased as much as 37%. The tensile strengths of the PP/ABS (70/30) blends after accelerated aging indicated a trend similar to that of the impact strength. The morphological studies indicated no significant changes in the PP/ABS (70/30) blends with SEBS-g-MAH; however, many cavities and damages were observed in the blend with SEBS. The above results suggest that SEBS-g-MAH acts as an impact modifier and as a good compatibilizer in the PP/ABS (70/30) blends.