Effect of nanosilica on the co-continuous morphology of polypropylene/polyolefin elastomer blends

This paper reports the effect of nanosilica (SiO2) on the morphology of co-continuous immiscible polypropylene (PP)/polyolefin elastomer (POE) blends. The unfilled blends display phase inversion and a co-continuous structure at a ratio of 50/50 PP/POE by weight. Upon addition of SiO2 in the presence of maleated PP compatibilizer a finer structure, consisting of elongated POE particles dispersed within the PP phase is obtained. This transformation is associated to the presence of finely dispersed SiO2 particles that are localized exclusively within the PP matrix. The impact properties, flexural and Young's moduli of the blends increase significantly, pointing to a synergistic effect arising from the presence of the reinforced PP phase, containing high amounts of the finely dispersed elastomeric phase.