Influence of β nucleation agent on the dispersion of nano‐CaCO 3 in isotactic polypropylene matrix

To study the interaction between β‐nucleation agent and nano‐CaCO 3 in iPP matrix, the dynamic rheology properties, crystallization and melting behaviors, impact fracture surface of β‐nucleation agent (β‐NA) nucleated and nano‐CaCO 3 filled iPP were investigated in details in this study. Under suitable conditions, the β‐NA has a “promoting dispersion effect” on the dispersion of nano‐CaCO 3 in PP matrix. However, 0.2 wt % β‐NA nucleated sample has a worse “promoting dispersion effect” than 0.05 wt % β‐NA nucleated sample at relatively high nano‐CaCO 3 content (7.5 wt %). The reason is that 0.2 wt % β‐NA aggregates on the surface of nano‐CaCO 3 agglomerations. The α crystals induced from β‐crystals grow more regular and perfect than conventional α crystals. For the relative fraction of β crystals ( K β ), the nano‐CaCO 3 content has little influence on 0.05 wt % β‐NA nucleated samples, but obvious effect on 0.2 wt % β‐NA nucleated samples. Based on the investigated results, a mechanism model about the interaction between β‐nucleation agent and nano‐CaCO 3 in iPP matrix is proposed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013