| Autor: |
Tasaka, Shigeru, Niki, Jun, Ojio, Takeaki, Miyata, Seizo |
| Zdroj: |
Polymer Journal; January 1984, Vol. 16 Issue: 1 p41-48, 8p |
| Abstrakt: |
Solid-state extrusion of poly(vinylidene fluoride) and its coextrusion with polyethylene were carried out using a slit die (die angle=35°) at 400 MPa. Extrudates with smooth surfaces were obtained at extrusion ratios from 2.0 to 6.5. Wide-angle X-ray diffractions of the extrudates showed double orientation characteristic of the form I crystals, with the c-axis preferentially oriented in the machine direction and the b-axis parallel to the film surface. The piezoelectric constant d31of the extrudates increased with increasing extrusion ratio, but decreased with increasing extrusion temperature. Thus, the piezoelectric activity may be explained by changes in Poisson’s ratio and Young’s modulus, perfection of crystallites, and selective orientation. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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