Fundamental Bonding Properties of Douglas-Fir and Southern Yellow Pine Wood

Abstract Bonding properties of southern yellow pine (Pinus spp.) and Douglas-fir (Pseudotsuga menziesii) were compared in terms of density, chemical composition, surface energy, shear stress, percent wood failure, and delamination. Specimens were taken from two trees of loblolly pine (Pinus taeda) and one tree of Douglas-fir. Density measurements showed that for mature wood, southern pine exhibited a higher average density than Douglas-fir, but for juvenile wood, southern pine showed a lower average density than Douglas-fir. Chemical analysis determined that southern yellow pine contained higher percent hemicellulose, lignin, and extractives, whereas Douglas-fir had higher percent cellulose. Static sessile drop contact angle measurements revealed that southern yellow pine specimens exhibited a lower average contact angle than Douglas-fir and, accordingly, higher average surface energy. Shear strength, percent wood failure, and delamination due to accelerated weathering were measured for bonded specimens c...