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The effect of nanoclays on the nucleation, crystallization, and melting mechanisms of isotactic polypropylene
Author(s) -
MedellínRodríguez F.J.,
MataPadilla J.M.,
Hsiao B.S.,
WaldoMendoza M.A.,
RamírezVargas E.,
SánchezValdes S.
Publication year - 2007
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20902
Subject(s) - crystallization , tacticity , materials science , nucleation , polypropylene , montmorillonite , chemical engineering , isothermal process , crystallization of polymers , polymer , composite material , nanocomposite , polymer chemistry , polymerization , thermodynamics , chemistry , organic chemistry , physics , engineering
The influence of organomodified nanoclay (montmorillonite) on the crystallization and melting mechanisms of isotactic polypropylene (iPP) was studied. Films of both neat polymer and clay nanocomposites were prepared after molecular weight optimization through melt extrusion. Products exhibited the tactoidlike morphology since no compatibilizers were used. The effect of introduction of nanoclay within the polymer was studied through isothermal crystallization and linear heating. The results indicated that low nanoclay concentrations induce the formation of the β‐crystalline structure, its formation being inhibited with high nanoclay contents. Dynamic nonisothermal bulk crystallization experiments indicated that nanoclays act as nucleating agents of iPP. Isothermal, bulk crystallization studies indicated that the crystallization process (induction time and crystallization kinetics) is proportionally accelerated by the nanoclay presence. There was also an accelerated formation of secondary crystallization when nanoclays were present in high concentrations. POLYM. ENG. SCI., 47:1889–1897, 2007. © 2007 Society of Plastics Engineers