Hygroscopic behaviour of lignocellulosic materials : Dataset at oscillating relative humidity variations
Résumé
The objective of this work is to study the hygroscopic behaviour of lignocellulosic materials used in building
insulation. Five lignocellulosic materials have been studied and compared: cellulose, flax-hemp wool, low fibreboard
density (LDF), Norway spruce and wheat straw. Particular attention is paid to the history of changes in
relative humidity (RH). The RH trajectories were chosen to meet two objectives: i) to precisely determine the
envelope curves (full adsorption and full desorption in the absence of memory effect) and ii) to quantify the
memory effect in the case of partial sorption cycles, likely to occur in these materials in use. The Hailwood-
Horrobin model was used to describe the envelope curves and the effect of temperature on isotherms was also
modelled. The difference in hygroscopic behaviour is explained by the differences in the chemical and structural
composition of the materials studied. The parameters identified in this work provide very useful information to
assess the sorption behaviour of lignocellulosic materials when in use in buildings.