Structure and properties of an oriented fluorosulfonated/PTFE copolymer
| Autor: | Marianne Gilbert, B. Haworth, D. J. B. Myers |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Annealing (metallurgy) General Chemistry Polymer law.invention chemistry.chemical_compound Crystallinity chemistry law Nafion Ultimate tensile strength Materials Chemistry Composite material Crystallization Thermal analysis Ionomer |
| Zdroj: | Polymer Engineering and Science. 44:272-282 |
| ISSN: | 1548-2634 0032-3888 |
| DOI: | 10.1002/pen.20026 |
| Popis: | This polymer is a precursor of Nafion, an ionomer developed for ion-selective membranes. In this work various stretching procedures were carried out on the precursor, in order to explore the possibilities of enhanced performance. First, the crystallization behavior and properties of the unoriented precursor were investigated. It was found that the precursor copolymer contains crystallinity, which melts over a very wide temperature range. The amount of crystallinity is modified both by thermal history and applied shear. Thermal analysis can be used to determine processing/ annealing temperatures for samples with unknown thermal history. It was found that the precursor possessed a maximum elongation at break at 70°C. Stretching was carried out at 70°C using a laboratory-based tentering process, to produce both uniaxial and biaxial films. Films were characterized to monitor their shrinkage behavior, and orientation was measured by birefringence. Their tensile properties were measured with respect to stretching direction. Using tentering, which is carried out at relatively low temperatures, large amounts of orientation were produced, resulting in a significant increase in tensile strength, and decrease in elongation at break. |
| Databáze: | OpenAIRE |
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