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Effect of nucleating agent addition on crystallization of isotactic polypropylene
Author(s) -
Feng Y.,
Jin X.,
Hay J. N.
Publication year - 1998
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/(sici)1097-4628(19980906)69:10<2089::aid-app20>3.0.co;2-w
Subject(s) - spherulite (polymer physics) , crystallization , tacticity , nucleation , materials science , supercooling , polymer chemistry , isothermal process , polarized light microscopy , chemical engineering , polypropylene , composite material , thermodynamics , polymer , polymerization , optics , engineering , physics
The isothermal and nonisothermal crystallization kinetics of nonnucleated and nucleated isotactic polypropylene (iPP) were investigated by DSC and a polarized light microscope with a hot stage. Dibenzylidene sorbitol (DBS) was used as a nucleating agent. It was found that the crystallization rate increased with the addition of DBS. The influence of DBS on fold surface energy, σ e , was examined by the Hoffman and Lauritzen nucleation theory. It showed that σ e decreased with the addition of DBS, suggesting that DBS is an effective nucleating agent for iPP. Ozawa's theory was used to study the nonisothermal crystallization. It was found that the crystallization temperature for the nucleated iPP was higher than that for nonnucleated iPP. The addition of DBS reduced the Ozawa exponent, suggesting a change in spherulite morphology. The cooling crystallization function has a negative exponent on the crystallization temperature. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2089–2095, 1998