Abstract: Isotactic polypropylene containing β-nucleating agent and glass fiber was prepared by conventional injection molding (CIM) and dynamic packing injection molding (DPIM), respectively. Molecular orientation of iPP, GF orientation, and crystallization behavior were characterized by wide angle X-ray diffraction (WAXD), scanning electronic microscopy (SEM), and small angle X-ray scattering (SAXS). It was found that the DPIM sample with 30 wt % GF and 0.2 wt % β-nucleating agent had the best mechanical properties, with the tensile strength achieved 58.52 MPa and the impact strength 9.26 kJ/m2. This could be attributed to the bamboo-like 'hard skin, soft core' bionic structure formed in the samples.

Key words: isotactic polypropylene, glass fiber, nucleating agent, composite, dynamic packing injection molding, structure