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Variable retention of water by dry wood
Author(s) -
Hergt H. F. A.,
Christensen G. N.
Publication year - 1965
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1965.070090703
Subject(s) - sorption , water content , water vapor , swell , moisture , wetting , cellulose , chemistry , materials science , composite material , organic chemistry , adsorption , thermodynamics , physics , geotechnical engineering , engineering
When small wood (or cellulose) samples are vacuum‐dried at room temperature, their final weight is found to vary according to their previous sorption history. The weight variations, of up to 1%, are shown to be due to strongly retained water. A minimum weight is obtained reproducibly (± 0.01%) only when the wood is dried rapidly from the wetted state. When wood thus dried is exposed to water vapor and redried, water is retained even after drying for long periods or at higher temperatures (65°C.) and is removed only by again wetting and redrying the wood. The quantity of water retained is greatest after exposure to relative vapor pressures of approximately 0.5 and increases linearly with the square root of time of exposure up to at least 1000 hr. As some of these phenomena have been reported for the wool–water system also, it is possible that other polymers, particularly those which swell in water, may behave similarly. The significance of these results for the experimental determination of moisture content and the study of water sorption is discussed.