The influence of photodegradation and weathering on the water vapour sorption kinetic behaviour of scots pine earlywood and latewood

The effect of weathering or accelerated photodegradation on the water vapour sorption kinetics of Scots pine (Pinus sylvestris) has been studied. The sorption kinetics were analysed using the parallel exponential kinetics (PEK) model and the parameters obtained used as input into a Kelvin-Voigt thereby providing values for the wood cell wall stiffness and viscosity. Differences in kinetic behaviour were found between earlywood and latewood samples, and between samples which had been photodegraded or weathered when compared to unexposed samples. The values for the cell wall stiffness are in general agreement with values previously published in the literature.