In situ reactive compatibilization of PP/ABS blends via Friedel-Crafts alkylation reaction

Friedel-Crafts alkylation reaction was employed to reactively compatibilize the polypropylene (PP)/acrylonitrile- butadiene-styrene (ABS) blends, using AlCl3 as a catalyst. Rheology, morphology and mechanical properties of the reactive compatibilized blends along with the reference un-compatibilized samples were studied. Scanning electron microscopy (SEM) observations showed that blends containing catalyst exhibited an improvement in the dispersion state of ABS rubber particles. The results of mechanical tests revealed that reactive compatibilization partly increased the ultimate strength and Izod impact strength of the blends with a loss in tensile ductility. The change in these properties was explained in terms of different chemical reactions including grafting and degradation. Occurrence of these reactions was confirmed using different viscoelastic properties of the compatibilized blend samples. A great improvement in ultimate strength and impact toughness to levels much higher than those of neat PP was achieved in reactively compatibilized PP/ABS blends containing PP-g-MA. These findings were justified by morphological and rheological analyses. The formation of graft copolymer was also confirmed using Fourier transform infrared spectroscopy (FTIR) measurements. The results of impact toughness data were in agreement with the interfacial tension values measured via contact angle analysis. The deformation behavior of the different compatibilized samples was rationalized via fractographic study of the impact-fractured surfaces.