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Crystallization kinetics and PVT behavior of poly(vinylidene fluoride) in process conditions
Author(s) -
Pantani R.,
Speranza V.,
Besana G.,
Titomanlio G.
Publication year - 2003
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.12622
Subject(s) - crystallization , crystallinity , materials science , amorphous solid , thermodynamics , crystallization of polymers , volume (thermodynamics) , compressibility , fluoride , extrusion , composite material , chemistry , crystallography , physics , inorganic chemistry
Abstract The so‐called fluoropolymers have gained, in recent years, considerable industrial success, and the increasing industrial interest in this class of materials has caused a need for better characterization of the properties of interest for processability, for instance, for injection molding or extrusion. In this work, the pressure–volume–temperature (PVT) relationship of a poly(vinylidene fluoride) is described by combining specific volumes of amorphous and crystalline phases present in the material. The volumes of the two phases are described simply by thermal expansion and compressibility coefficients drawn from standard PVT data below and above the crystallization range. Within the crystallization range, the material volume is assumed to change from amorphous to crystalline according to the evolution of an overall crystallinity degree, which is described by the Nakamura nonisothermal formulation of an Avrami crystallization kinetic model. Model parameters are identified by comparison with standard calorimetric results, PVT data, and final densities of thin samples solidified during quenches conducted with cooling rates of several hundreds of Kelvins/second. The resulting model allows the description of the PVT behavior of PVDF in the pressure ‐and cooling‐rate ranges of interest for processing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3396–3403, 2003