The effect of acetylation on the mechanical properties, hydrophobicity, and dimensional stability ofPinus sylvestris

Summary

Strips and blocks ofPinus sylvestris were acetylated for different periods of time. These, along with control samples, were tested for their tensile modulus, hydrophobicity and dimensional stability. The modulus of elasticity (tensile modulus) for each sample was derived using a statistical approach. The observations in this work suggest that the acetylation process significantly reduces the tensile modulus of the wood compared to its untreated state in an irreversible manner, and that the extent of the deterioration in tensile modulus is a function of the acetylation conditions. Acetylation improved significantly the hydro-phobicity and the dimensional stability of the wood as measured by the roll angle and swelling tests respectively. It appears therefore that acetylation using acetic anhydride in xylene has an optimum set of reaction conditions that compromise between the gains in water repellence and dimensional stability with the deterioration in mechanical properties.