Research On Crystalization Behavior Of Nano-ZnO/Glass Fiber/Polypropylene Composites

Polypropylene (PP) is widely used in many fields, such as automobiles, medical, office,pipe and architecture. However, its high brittle transformation temperature, low mechanical strength, dyeing property, antistatic property, and poor impact resistance, considerably limit its further applications.The nano-ZnO treated by surface-coupling KH-550 or oleic acid and glass fiber were introduced to improve the mechanical performance and melt index of PP. Nano-ZnO/glass fiber/PP composites were fabricated by melt blending.The crystalization behavior structure of nano-ZnO/glass fiber/PP composites was analyzed by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and polarized light microscopy (PLM). The surface characteristics of the surface-coupled nano-ZnO and the impact fractograph of nano-ZnO/glass fiber/PP composites were observed respectively with the aid of Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM) and scanning electron micrograph (SEM). In addition, the effect of crystalization behavior on the mechanical properties of nano-ZnO/glass fiber/PP composites was investigated.The results indicated that nano-ZnO surface-coupled by oleic acid could be uniformly dispersed in PP matrix. The incorporation of nano-ZnO and glass fiber result in increase of the crystallization temperature and crystallization rate of PP and decrease in the crystallize degree and grain size of composites. Furthermore, some part of crystal modality of PP transformed fromα-crystal toβ-crystal. Finally, the synergistic effect on nano-ZnO and glass fiber enhanced the tensile strength and impact toughness of hybrid composites. Meantime, the fluidity of the composites was improved. It was found that the composites composed of 1% nano-ZnO and 30% glass fiber possessed the tensile strength of 95.15MPa, impact toughness of 7.84kJ/m2 and melt index of 17.90g/10min.