Surface Modification of CaCO_3 Micro/Nanofillers by Pimelic Acid: Consequences on Crystallization Behaviors of Polypropylene Composites

摘要

In present study, two kinds of CaCO_3 with micro-sized and nanometer-sized particles were treated by pimelic acid (PA) with different proportion. Then the treated particles (the total content of micro-sized and nanometer-sized CaCO_3 particles was 10 wt%) were mixed with polypropylene (PP) to prepare CaCO_3/PP composites by melting blending. The crystallization behavior and morphology of composites were studied by wide-angle-X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized microscope (PLM), respectively. Compared with PP and other samples, the content of β-crystal in the composite NCP2 where the ratio of nano and micro particles was 2:8 (NCP2), reached the highest values. The growth speed of crystals in PP matrix was much quicker, leading to the larger spherulites than the NCP2 and NCP8. The time of complete nucleation for NCP8 was lower than PP, but higher than NCP2.