Crystallization and melting behavior of β-nucleated isotactic polypropylene/polyamide 6 blends with maleic anhydride grafted polyethylene-vinyl acetate as a compatibilizer

Abstract

β-Nucleated isotactic polypropylene (β-iPP) blend with maleic anhydride grafted polyethylene-vinyl acetate (EVA-g -MA) and β-iPP/polyamide (PA) 6 blend, as well as its compatibilized version with EVA -g-MA as a compatibilizer were prepared with an internal mixer. Analysis from differential scanning calorimeter (DSC) and wide angle X-ray diffraction (WAXD) indicates that the addition of EVA-g-MA into β-nucleated iPP decreases the crystallization temperature ( T c p) of PP, but it has no pronounced influence on the β-crystal content for β-nucleated iPP. For β-nucleated iPP/PA6 blends, PA6 obviously decreases the β-crystal content. However, the addition of EVA-g-MA is quite benefit for the formation of β-crystal in β-nucleated iPP/PA6 blends and the β-crystal content increases with increasing EVA-g-MA content. It is suggested that the nucleating agent mainly disperses in the PA6 phase and/or the interface between iPP and PA6 in iPP/PA6 blend, which was proved by etching the blends with sulfuric acid and experimental facts from SEM.