Non-isothermal crystallization behavior of polypropylene with nucleating agents and nano-calcium carbonate

The non-isothermal crystallization kinetics of isotactic polypropylene (iPP) and nucleated iPP was investigated by DSC. The crystalline morphology of iPP was observed by polarized light microscopy. It was found that the crystallization rate increased with the addition of nanometer-scale calcium carbonate (nm-CaCO3) particles. The addition of dibenzylidene sorbitol (DBS) could greatly reduce the spherulite size of W. The crystallization temperature for the iPP with DBS was higher than for non-nucleated W. DBS was an effective nucleating agent for W. The results of measurements suggested that there was a coordinated action to the crystallization of iPP when the organic nucleating agents (DBS) and nm-CaCO3 were added to iPP together. Comparison to the modified Avrami equation and Ozawa equation, another method-Mo's method can describe the non-isothermal crystallization behavior of iPP and nucleated iPP more satisfactorily. (c) 2005 Elsevier Ltd. All rights reserved.