Enhanced Thermal and Mechanical Properties of Polypropylene Composites with Hyperbranched Polyester Grafted Sisal Microcrystalline

Polypropylene composites were prepared by melt compounding method with hyperbranched polyester grafted sisal microcrystalline and CaCO3. The thermal and mechanical properties of polypropylene composites were investigated by means of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), melt flow indexer (MFI), dynamic mechanical analysis (DMA) and mechanical tests. It was found that the thermal and mechanical properties of PP composites were greatly improved by incorporating MCC-g-HPG-SA. For example, the impact strength, flexural strength, and toughness of the composites with 4 wt% MCC-g-HPG-SA loading were 64.71 kJ/m(2), 42.72 MPa, and 2186.69 J/m(3), significantly increased by 238.3 %, 18.4 % and 1843.9 % respectively, as compared with PP/MCC/CaCO3 composites. In addition, thermal stability of PP/MCC-g-HPG-SA/CaCO3 composites also showed an obvious enhancement compared with PP/MCC/CaCO3 composites.