Tailoring poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) microstructure and physicochemical properties by exploring its binary phase diagram with dimethylformamide |
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| Authors: | Carlos. M. Costa Ana V. Machado Maria M. Silva Senentxu Lanceros‐Mendez |
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| Affiliation: | 1. Departamento/Centro de Física, Universidade do Minho Campus de Gualtar, Braga, Portugal;2. IPC—Institute for Polymers and Composites, Universidade do Minho, Campus de Azurém, Guimar?es, Portugal;3. Departamento/Centro de Química, Universidade do Minho Campus de Gualtar, Braga, Portugal |
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| Abstract: | Poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) (PVDF‐CTFE) membranes were prepared by solvent casting from dimethylformamide (DMF). The preparation conditions involved a systematic variation of polymer/solvent ratio and solvent evaporation temperature. The microstructural variations of the PVDF‐CTFE membranes depend on the different regions of the PVDF‐CTFE/DMF phase diagram, explained by the Flory‐Huggins theory. The effect of the polymer/solvent ratio and solvent evaporation temperature on the morphology, degree of porosity, β phase content, degree of crystallinity, mechanical, dielectric, and piezoelectric properties of the PVDF‐CTFE polymer were evaluated. In this binary system, the porous microstructure is attributed to a spinodal decomposition of the liquid‐liquid phase separation. For a given polymer/solvent ratio, 20 wt % , and higher evaporation solvent temperature, the β phase content is around 82% and the piezoelectric coefficient, d33, is ? 4 pC/N © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 761–773 |
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| Keywords: | membranes phase diagrams fluoropolymers |
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