Effect of Zeolite 5A on the Crystalline Polypropylene (PP) in PP/β-Nucleating Behavior of Agent System

The effect of zeolite 5A on the crystalline behavior of polypropylene (PP) in PP/beta-nucleating agent system was investigated with X-ray diffractometer (XRD), differential scanning calorimeter (DSC), and polarized light microscope (PLM) in this study. Zeolite 5A has less effect on crystalline phase of PP/beta-nucleating agent than does n-CaCO3, which is ascribed to the stronger surficial polarity and better dispersibility of zeolite 5A. The data of DSC indicated that the crystallization peak temperature of PP increases by 8.3 degrees C in the presence of zeolite 5A, and n-CaCO3 increases 5.7 degrees C in PP/TMB-5 system, relative to pure PP. And the initial crystallization temperature (T-c0) and the relative crystallinity (X-c) of PP is much more dramatically raised in the presence of zeolite 5A than CaCO3. The efficiency of zeolite 5A in reducing the spherulites size of PP was seen clearly from the PLM photographs. The mechanical testing results showed that the flexural strength and impact strength of PP/beta-nucleating agent system increased in the presence of zeolite 5A. POLYM. COMPOS., 29:1291-1296, 2008. (C) 2008 Society of Plastics Engineers