Nonisothermal crystallization and melting behavior of β-nucleated isotactic polypropylene and polyamide 66 blends

A highly novel nano-CaCO 3 supported β-nucleating agent was employed to prepare β-nucleated isotactic polypropylene (iPP) blend with polyamide (PA) 66, β-nucleated iPP/PA66 blend, as well as its compatibilized version with maleic anhydride grafted PP (PP-g-MA), maleic anhydride grafted polyethylene-octene (POE-g-MA), and polyethylene-vinyl acetate (EVA-g-MA), respectively. Nonisothermal crystallization behavior and melting characteristics of β-nucleated iPP and its blends were investigated by differential scanning calorimeter and wide angle X-ray diffraction. Experimental results indicated that the crystallization temperature (T cp) of PP shifts to high temperature in the non-nucleated PP/PA66 blends because of the α-nucleating effect of PA66. T cp of PP and the β-crystal content (K β) in β-nucleated iPP/PA66 blends not only depended on the PA66 content, but also on the compatibilizer type. Addition of PP-g-MA and POE-g-MA into β-nucleated iPP/PA66 blends increased the β-crystal content; however, EVA-g-MA is not benefit for the formation of β-crystal in the compatibilized β-nucleated iPP/PA66 blend. It can be relative to the different interfacial interactions between PP and compatibilizers. The nonisothermal crystallization kinetics of PP in the blends was evaluated by Mo's method.