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Nonisothermal crystallization kinetics of polytetrafluoroethylene
Author(s) -
Seo Yongsok
Publication year - 2000
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.11257
Subject(s) - crystallization , nucleation , materials science , crystallite , polytetrafluoroethylene , activation energy , kinetics , composite material , chemical engineering , polymer chemistry , thermodynamics , chemistry , metallurgy , quantum mechanics , engineering , physics
An analysis of the crystallization kinetics of polytetrafluoroethylene (PTFE) under nonisothermal conditions is presented. A simple method is proposed to remove the limits of the Ozawa theory. The Avramic exponent, n , can be reasonably well determined from the nonisothermal crystallization exotherm. An n value of ∼1.49 was obtained for PTFE, which indicates the formation of one‐dimensional crystallites (fibrillar type) after thermal nucleation or two‐dimensional crystallites (discs) after athermal nucleation. Both these morphologies were experimentally observed. For PTFE crystallization from the melt, activation energy was obtained as 34 kcal/mol. This is much smaller than those of PEEK and PET, indicating a very fast crystallization of PTFE.