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Rheologica Acta

, Volume 31, Issue 4, pp 381–389 | Cite as

Rheological behavior of water-creosote and creosote-water emulsions

  • C. Tiu
  • A. K. Podolsak
  • T. N. Fang
  • J. B. Watkins
Original Contributions

Abstract

The effect of temperature on the steady-shear viscosity of two base emulsions (water-in-creosote (w/o) and creosote-in-water (o/w)) and a pigment emulsified creosote (PEC) was investigated. The PEC is a water-in-creosote emulsion which contains also a solid, micronised pigment, and is used industrially as a wood preservative. All three emulsions exhibited shear thinning characteristics at different temperatures. The viscosity-shear rate relationships follow a modified Quemada model. A temperature-superposition method using the reduced variables η/η and t c \(\dot \gamma\) was applied to yield a master plot for each of these emulsions at different temperatures. The effect of creosote concentration on the viscosity of four other o/w emulsions at different temperatures was also studied. The same reduced variables were able to produce a temperature-concentration superposition plot for all of the o/w emulsion results.

The effective (average) radius of the globules (dispersed phase) was found to increase with increasing temperature for the base w/o and the PEC emulsion. The collision theory could be used to explain the increase in the droplet size. However, while little overall variation in globule size was observed for the o/w emulsions, microscopic observation indicated an increase in the proportion of large diameter droplets with temperature at the highest creosote concentration (60%). A “creaming” effect (phase concentration) was observed with these emulsions at higher temperatures, precluding an accurate estimate of droplet size based on collision theory.

Key words

Creosote/water emulsion wood preservative steady shear properties temperature and concentration effects 

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References

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Copyright information

© Steinkopff-Verlag 1992

Authors and Affiliations

  • C. Tiu
    • 1
  • A. K. Podolsak
    • 1
  • T. N. Fang
    • 2
  • J. B. Watkins
    • 3
  1. 1.Department of Chemical EngineeringMonash UniversityClaytonAustralia
  2. 2.Department of Chemical EngineeringEast China University of Chemical TechnologyShanghaiChina
  3. 3.Division of Forestry and Forest ProductsCSIROClaytonAustralia

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