Influence of the Solvent Evaporation Rate on the Crystalline Phases of Solution-Cast Poly(Vinylidene Fluoride) Films
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Data
2010-04-15
Autores
Chinaglia, Dante Luis [UNESP]
Gregorio, Rinaldo
Stefanello, Josiani Cristina [UNESP]
Pisani Altafim, Ruy Alberto
Wirges, Werner
Wang, Feipeng
Gerhard, Reimund
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John Wiley & Sons Inc
Resumo
The influence of the solvent-evaporation rate on the formation of of. and P crystalline phases in solution-cast poly(vinylidene fluoride) (PVDF) films was systematically investigated. Films were crystallized from PVDF/N,N-dimethylformamide solutions with concentrations of 2.5, 5.0, 10, and 20 wt % at different temperatures. During crystallization, the solvent evaporation rate was monitored in situ by means of a semianalytic balance. With this system, it was possible to determine the evaporation rate for different concentrations and temperatures of the solution under specific ambient conditions (pressure, temperature, and humidity). Fourier-Transform InfraRed spectroscopy with Attenuated Total Reflectance revealed the P-phase content in the PVDF films and its dependence on previous evaporation rates. Based on the relation between the evaporation rate and the PVDF phase composition, a consistent explanation for the different amounts of P phase observed at the upper and lower sample surfaces is achieved. Furthermore, the role of the sample thickness has also been studied. The experimental results show that not only the temperature but also the evaporation rate have to be controlled to obtain the desired crystalline phases in solution-cast PVDF films. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 785-791, 2010
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FT-IR, nucleation, poly(vinylidene fluoride), (PVDF), polymorphism, evaporation rate
Como citar
Journal of Applied Polymer Science. Hoboken: John Wiley & Sons Inc, v. 116, n. 2, p. 785-791, 2010.