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Influence Of Annealing On Microstructure And Mechanical Properties Of Isotactic Polypropylene With β-Phase Nucleating Agent
Published 2009 · Chemistry
The microstructure and mechanical properties of β-nucleated iPP before and after being annealed at different temperatures (90−160 °C) have been analyzed. Annealing induced different degrees of variation in fracture toughness of β-nucleated iPP samples, namely, slight enhancement at relatively low annealing temperatures ( 140 °C) has been observed. The variation of fracture toughness of β-nucleated iPP is observed to be dependent on the content of β-NA. Experiments, including scanning electronic microscope (SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), and dynamic mechanical analysis (DMA), are performed to study the variations of microstructures as well as the toughening mechanism of the β-nucleated iPP after being annealed. The results indicate that the decreased number of chain segments in the amor...