● DOI: https://doi.org/10.1515/hf-2016-0097

Abstract:   The hygroscopic properties of Pinus pinea L. wood at 35 and 50ºC were investigated by the dynamic vapour sorption (DVS) technique. The sorption kinetic behaviour was studied through the parallel exponential kinetics (PEK) model, which is subdivided into a fast and a slow process. The parameters obtained by PEK were interpreted based on the Kelvin-Voigt (KV) model to determine elasticity and viscosity values of the wood cell wall. The PEK data perfectly fit the experimental data. The temperature dependent transition between the fast and slow processes is fluent. The slow process contributes more to the total hysteresis of sorption. The kinetic properties varied in relation to the type of cycle and the temperature. The moduli of elasticity and viscosity were higher in the slow process than in the fast one. In both processes, the moduli showed a decreasing tendency in relation to relative humidity.