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Cocrystallization of ethylene/1-octene copolymer blends during crystallization analysis fractionation and crystallization elution fractionation

Authors

  • Kanokpon Suriya,

    1. Center of Excellence for Petroleum, Petrochemicals and Advanced Materials (PPAM), Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, 50 Phaholyothin Rd., Jatujak, Bangkok 10900, Thailand
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  • Siripon Anantawaraskul,

    Corresponding author
    1. Center of Excellence for Petroleum, Petrochemicals and Advanced Materials (PPAM), Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, 50 Phaholyothin Rd., Jatujak, Bangkok 10900, Thailand
    2. Center for Advanced Studies in Nanotechnology and Its Applications in Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
    • Center of Excellence for Petroleum, Petrochemicals and Advanced Materials (PPAM), Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, 50 Phaholyothin Rd., Jatujak, Bangkok 10900, Thailand
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  • João B. P. Soares

    1. Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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Abstract

Blending of ethylene/1-octene copolymers can be used to achieve a well-controlled broad chemical composition distribution (CCD) required in several polyolefin applications. The CCD of copolymer blends can be estimated using crystallization analysis fractionation (CRYSTAF) or crystallization elution fractionation (CEF). Unfortunately, both techniques may be affected by the cocrystallization of chains with different compositions, leading to profiles that do not truly reflect the actual CCD of the polymer. Therefore, understanding how the polymer microstructure and the analytical conditions influence copolymer cocrystallization is critical for the proper interpretation of CRYSTAF and CEF curves. In this investigation, we studied the effect of chain crystallizabilities, blend compositions, and cooling rates on cocrystallization during CEF and CRYSTAF analysis. Cocrystallization is more prevalent when the copolymer blend has components with similar crystallizabilities, one of the components is present in much higher amount, and fast cooling rates are used. CEF was found to provide better CCD estimates than CRYSTAF in a much shorter analysis time. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011

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