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Rheologica Acta

, Volume 9, Issue 2, pp 299–305 | Cite as

Dielectric properties of the composite system polyurethane — sodium chloride

  • P. H. Ong
Article

Summary

The dielectric properties of the composite system polyurethane-sodium chloride have been measured at frequencies between 10−4 Hz and 3 · 105 Hz in the temperature range from −150 °C up to +90 dgC. Three dielectric loss mechanisms have been found; they are indicated byα1,α2 andβ. The activation energy of theα1-transition is 35 kcal/mole, that of theβ-transition 6.7 kcal/mole. Theα2-loss peak was only observed at frequencies of 103 Hz and higher, forming one broad peak with theα1-loss peak at lower frequencies. In the composite materials, theβ- andα2-loss peaks measured at fixed frequencies were found at the same temperature. Theα2-loss peak, however, was shifted to a lower temperature, due to the sodium chloride filler. Comparison of experimental data ofε′ and tanδ with theoretical predictions concerning the dielectric properties of composite systems showed only partial agreement. The difference mainly consisted in. the temperature shift in the tanδ-peak of theα1-transition.

Keywords

Polymer Chloride Activation Energy Sodium Chloride Composite Material 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Zusammenfassung

Die dielektrischen Eigenschaften des Verbundssystems Kochsalz-Polyurethankautschuk wurden im Frequenzgebiet zwischen 10−4 Hz und 3.105 Hz und im Temperaturbereich von −150 °C bis +90 °C gemessen. Es wurden drei dielektrische Verlustmaxima gefunden, die mitα1,α2 undβ angedeutet werden. Die Aktivierungsenergie desα1-Überganges beträgt 35 kcal/Mol, die desβ-Überganges 6.7 kcal/Mol. Dasα2-Maximum konnte nur bei Frequenzen höher als 103Hz vomα1-Maximum gesondert erfaßt werden. Die Lage derα2- undβ-Maxima war vom Füllgrad unabhängig. Dasα1-Maximum verschiebt sich mit steigendem Füllgrad zu niedrigeren Temperaturen. Die gemessenen Werte vonε′ und tanδ stimmen nur teilweise mit den Aussagen einer Theorie der dielektrischen Eigenschaften von Mischkörpern überein.

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Copyright information

© Dr. Dietrich Steinkopff Verlag 1970

Authors and Affiliations

  • P. H. Ong
    • 1
  1. 1.Centraal Laboratorium TNO DelftNetherlands

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