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Publications (2)0 Total impact

  • H. Lefebvre, F. Bauer, L. Eyraud
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    ABSTRACT: Thermal stability studies of PVDF polymer are presented. A high hydrostatic pressure cell is designed in order to apply simultaneously high pressure and high temperature up to 3500 bar and 300°C respectively. A high percentage of the Extended β-polar form can be induced by crystallization of PVDF films under high temperature and high hydrostatic pressure. Dielectric, piezoelectric and electroacoustic characteristics of poled β-ECC PVDF films are given. The stability of the piezoelectric activity of these poled PVDF films is enhanced for temperatures up to 150°C, i.e. 60°C higher than drawn PVDF film.
    Ferroelectrics. 09/1995; 171(1-4):259-269.
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    ABSTRACT: Studies in progress undertaken to increase the precision of the polarization of shock-compressed PVDF (polyvinylidene fluoride) and to develop optimum sensors and shock gauge package designs are described. Results obtained on such carefully prepared PVDF shock gauges show that differences in electrical charge response of less than a few percent are observed at 10 and 25 GPa. PVDF stress rate gauges show continuous response with high reproducibility to pressures approaching 35 GPa. It appears that low inductance electrode lead designs and reproducible remanent polarization are significantly improving the precision of the piezoelectric response of the PVDF gauges under shock loading, especially for the 3-mm×3-mm gauges. However, more work needs to be done to develop sensors with small active areas (1 mm<sup>2</sup>) with the same precision in polarization. Control of sensor loading rate with thickness of insulating film appears to offer potential for more reliable response. These results show that selected and precisely poled PVDF can respond precisely to pressures of 25 GPa
    Applications of Ferroelectrics, 1992. ISAF '92., Proceedings of the Eighth IEEE International Symposium on; 01/1992