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Nonisothermal bulk crystallization and subsequent melting behavior of syndiotactic polypropylenes: Crystallization from the melt state
Author(s) -
Supaphol Pitt
Publication year - 2000
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 - 10.1002/1097-4628(20001010)78:2<338::aid-app140>3.0.co;2-y
Subject(s) - crystallization , tacticity , thermodynamics , materials science , exponent , activation energy , avrami equation , polypropylene , polymer , kinetics , atmospheric temperature range , crystallization of polymers , polymer chemistry , kinetic energy , composite material , chemistry , polymerization , physics , linguistics , philosophy , quantum mechanics
Various macrokinetic models, namely, the Avrami, the Tobin, and the Ozawa models, were applied to describe the crystallization process of syndiotactic polypropylene (s‐PP) under nonisothermal conditions. Both Avrami and Tobin models were shown to provide a fair description of the experimental data. The Avrami exponent n a was found to range from 2.4 to 5.3, while the Tobin exponent n t was found to range from 3.1 to 6.7. The Ozawa model was found to describe the nonisothermal crystallization kinetics of s‐PP very well. The Ziabicki's kinetic crystallizability, suggesting the crystallization ability of polymers from the melt when cooled at a unit cooling rate, was also evaluated and was found to range from 0.93 to 1.40°C s −1 . The energy barrier for nonisothermal crystallization, based on the Augis–Bennett method, was found to range from −78.6 to −108.1 kJ mol −1 . © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 338–354, 2000