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Influence of Surface Carbon Deposition on the Bulk Crystallization of Isotactic Polypropylene
Author(s) -
Liu Jichun,
Li Huihui,
Duan Yongxin,
Jiang Shidong,
Miao Zhenjiang,
Wang Jijun,
Yan Shouke
Publication year - 2004
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200300196
Subject(s) - materials science , crystallization , tacticity , nucleation , crystallinity , recrystallization (geology) , optical microscope , scanning electron microscope , chemical engineering , carbon fibers , composite material , differential scanning calorimetry , polymerization , chemistry , polymer , organic chemistry , paleontology , thermodynamics , physics , engineering , biology , composite number
Summary: The effect of a surface‐vacuum‐evaporated ultrathin carbon layer on the bulk crystallization behavior of isotactic polypropylene (iPP) films was investigated by means of polarized optical microscopy, differential scanning calorimetry (DSC), and wide‐angle X‐ray diffraction. Results obtained from both isothermal crystallization and constant cooling experiments indicate that surface carbon deposition on an iPP film can remarkably increase the crystallization ability of it during the melt recrystallization process. Optical microscopy observations show that the melt recrystallization of iPP with a carbon coating starts about 10 °C earlier than the pure iPP during a re‐cooling process of 1 °C · min −1 . Under isothermal crystallization conditions, a much shorter induction period for nucleation is required for the carbon‐coated iPP than the non‐carbon‐coated one. The wide‐angle X‐ray diffraction and DSC analyses further demonstrate a crystallinity increment of the carbon‐coated iPP with respect to its non‐carbon‐coated counterpart. This clearly indicates that the strong influence of the interfacial interaction between the vacuum‐evaporated carbon and the iPP film on its bulk crystallization can be extended deep into the bulk material.An OM micrograph of a hot‐pressed partially carbon‐coated (top half) iPP film.