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Study on thermal behavior of impact polypropylene copolymer and its fractions
Author(s) -
Zhang Chunhui,
Shangguan Yonggang,
Chen Ruifen,
Zheng Qiang
Publication year - 2010
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.32827
Subject(s) - polypropylene , copolymer , materials science , tacticity , polyethylene , ethylene , crystallization , polymer chemistry , nucleation , annealing (glass) , ethylene propylene rubber , fractionation , differential scanning calorimetry , crystallinity , chemical engineering , composite material , polymer , polymerization , chemistry , chromatography , organic chemistry , thermodynamics , physics , engineering , catalysis
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 ( F 50 ) 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 ( F 100 ) 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 F 100 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