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The impact of polypropylene‐ graft ‐maleic anhydride on the crystallization and dynamic mechanical properties of isotactic polypropylene
Author(s) -
Harper David P.,
Laborie MariePierre G.,
Wolcott Michael P.
Publication year - 2008
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.29100
Subject(s) - polypropylene , materials science , differential scanning calorimetry , dynamic mechanical analysis , maleic anhydride , tacticity , copolymer , nucleation , crystallization , glass transition , composite material , melting point , polymer , polymer chemistry , chemical engineering , chemistry , polymerization , thermodynamics , organic chemistry , physics , engineering
Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used to identify the mechanisms that lead to differences in the mechanical behavior of formulations of polypropylene blended with maleated polypropylene (MAPP) copolymers. MAPP lowered the melting temperature of PP indicating that less stable crystals were formed possibly because of cocrystallization of PP and MAPP. Crystallization kinetics revealed that copolymers do not change the rate of crystal growth, but may retard nucleation leading to a more spherulitic morphology. The dynamic storage modulus slightly increased in the glassy region with the small addition amounts of MAPP, while mechanical dampening systematically decreased with MAPP addition. An analysis of the viscoelastic behavior did not reveal any real differences in molecular coupling around the β‐transition of PP with the addition of the MAPP copolymer. At low addition levels, MAPP does not appear to have a significant impact on the viscoelastic properties of the polymer blend. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009