Skip to main content
U.S. flag

An official website of the United States government

Correlation of water vapor adsorption behavior of wood with surface thermodynamic properties

Informally Refereed

Abstract

To improve the overall performance of wood-plastic composites, appropriate technologies are needed to control moisture sorption and to improve the interaction of wood fiber with selected hydrophobic matrices. The objective of this study was to determine the surface thermodynamic characteristics of a wood fiber and to correlate those characteristics with the fiberas water vapor adsorption behavior. The surface thermodynamic properties, determined by inverse gas chromatography at infinite dilution or near zero surface coverage, were the dispersive component of the surface energy, surface acid-base free energy and enthalpy of desorption of acid-base probes, and surface acid-base acceptor and donor parameters (KA and KD). Water vapor adsorption was expressed in terms of the percentage of weight gain (D W%) resulting from water vapor adsorption on the wood particles, calculated relative to their initial weight after preconditioning in a vacuum dessicator at room temperature. The results showed a strong correlation between DW% and KA, and between DW% and surface acid-base free energy of water desorption (DHAB water), calculated from experimental KA and KD and values in the literature for acceptor and donor values of water. These results suggest that for substrates such as wood, whose surface Lewis acid-base properties are characterized by a relatively stronger tendency to accept electrons, the key to controlling water vapor adsorption is to manipulate the magnitude of DH AB water, primarily via KA, and to a lesser extent via KD.

Keywords

Wood, Adsorption, Water vapor, Gas chromatography, Thermodynamics

Citation

Tshabalala, Mandla A.; Denes, Agnes R.; Williams, R. Sam. 1999. Correlation of water vapor adsorption behavior of wood with surface thermodynamic properties. Journal of applied polymer science. Vol. 73, no. 3 (July 18, 1999).:p. 399-407.
Citations
https://www.fs.usda.gov/research/treesearch/5957