Study on thermal behavior of impact polypropylene copolymer and its fractions

Authors

  • Chunhui Zhang,

    1. Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China
    2. Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
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  • Yonggang Shangguan,

    Corresponding author
    1. Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China
    2. Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
    • Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China
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  • Ruifen Chen,

    1. Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China
    2. Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
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  • Qiang Zheng

    Corresponding author
    1. Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China
    2. Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
    • Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China
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Abstract

An impact polypropylene copolymer (IPC) was fractionated into three fractions using n-octane as solvent by means of temperature-gradient extraction fractionation. The glass transitions, melting, and crystallization behavior of these three fractions were studied by modulated differential scanning calorimeter (MDSC) and wide-angle X-ray diffraction (WAXD). In addition, successive self-nucleation and annealing (SSA) technique was adopted to further examine the heterogeneity and the structure of its fractions. The results reveal that the 50°C fraction (F50) mainly consists of ethylene-propylene random copolymer and the molecular chains may contain a few of short but crystallizable propylene and/or ethylene unit sequences; moreover, the lamellae thicknesses of the resulting crystals are extremely low. Furthermore, 100°C fraction (F100) mainly consist of some branched polyethylene and various ethylene-propylene block copolymers in which some ethylene and propylene units also randomly arrange in certain segments, and some polypropylene segments can form crystals with various lamellae thickness. An obvious thermal fractionation effect for F100 samples after being treated by SSA process is ascribed to the irregular and nonuniform arrangement of ethylene and propylene segments. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

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