Capacitance dilatometry for the in-situ controlled expansion process of the cellular polymer-filler composites (ferroelectrets)

Johann Leonhartsberger, Harald Salhofer, Reinhard Schwödiauer, Simona Bauer-Gogonea, Siegfried Bauer, Reinhard Fostner, Gerhard Eder, Mika Paajanen, Hannu Minkkinen, Jaakko Raukola

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7 Citations (Scopus)

Abstract

Ferroelectrets are unusual composites, consisting of a closed-cell polymer-filler foam structure. Ferroelectrets behave like ferroelectric materials during and after internally charging the voids of the cellular structure. In order to optimize the electromechanical properties of ferroelectrets, the voids within the cellular polymer composite are expanded in a controlled manner in a high pressure gas chamber. Thereby, the gas pressure is first increased, subsequently released and finally the expanded structure is stabilized by a heat setting treatment at elevated temperatures. Capacitance dilatometry provides an easy means for the in-situ monitoring of the multi-step foaming process, and therefore allows for the control of the degree of foaming. The mechanical stabilization of the expanded cellular polymer composite structure is explained in terms of the enhanced crystallinity as a result of the heat setting process.
Original languageEnglish
Pages (from-to)181-187
Number of pages7
JournalFerroelectrics
Volume331
Issue number1
DOIs
Publication statusPublished - 2006
MoE publication typeA1 Journal article-refereed

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Keywords

  • piezoelectricity
  • ferroelectricity
  • polymer-filler composites

Cite this

Leonhartsberger, J., Salhofer, H., Schwödiauer, R., Bauer-Gogonea, S., Bauer, S., Fostner, R., Eder, G., Paajanen, M., Minkkinen, H., & Raukola, J. (2006). Capacitance dilatometry for the in-situ controlled expansion process of the cellular polymer-filler composites (ferroelectrets). Ferroelectrics, 331(1), 181-187. https://doi.org/10.1080/00150190600737735