Rheological properties and interfacial tension of polypropylene–poly(styrene-co-acrylonitrile) blend containing compatibilizer

Rheological and morphological properties of the polypropylene (PP) and poly(styrene-co-acrylonitrile) (SAN) blend containing polypropylene-g-poly(styrene-co-acrylonitrile) (PP-g-SAN) was studied by advanced rheometric expansion system (ARES) and scanning electron microscopy (SEM). Blends of the PP–SAN (20/80) with compatibilizer of the PP-g-SAN, ranging from 0 to 20 wt% (phr) were prepared using a twin screw extruder. In the study of the complex viscosity of the PP–SAN (20/80) blend, the complex viscosity of the blend showed maximum value in the 1.0 phr PP-g-SAN copolymer content, which suggested that the compatibilizing effect of the PP-g-SAN copolymer was achieved. From the morphological studies, the PP–SAN (20/80) blend showed droplet dispersion type morphology, and the PP droplet size showed minimum value (0.44 μm) in the 1.0 phr PP-g-SAN copolymer content. The interfacial tension of the PP–SAN (20/80) blend was determined from the morphological studies and form relaxation time using the Palierne and the Choi and Schowalter models and showed minimum value in the 1.0 phr PP-g-SAN copolymer content in each models. The results of the interfacial tension was consistent with the results obtained from the rheological and morphological studies of the PP–SAN (20/80) blend. From the results of the morphological, rheological studies and the values of the interfacial tension, it was suggested that the compatibility of the PP–SAN (20/80) blend increased more in the 1.0 phr PP-g-SAN copolymer content.