Effects of a Partial Hydrolysis on the Stiffness and Mass Loss of Three Southern Hardwoods‪.‬

Abstract Red oak, sweetgum, and yellow-poplar lumber was machined into 3 by 15 by 150-mm (tangential by radial by longitudinal) miniature beams. Moisture content was determined from a subset for calculating the ovendry weight of test samples prior to treatment. Samples were weighed, water saturated, and subjected to a partial hydrolysis at 150[degrees]C for 30 minutes in 1 percent sulfuric acid, water, or 1 percent sodium hydroxide solutions. Untreated controls were also used. The beams were ovendried to a constant weight, and then the modulus of elasticity, density, and mass loss (ML) were determined. Modulus of elasticity values were corrected to eliminate density variation by calculating the specific modulus of elasticity (SM) for property comparisons. The species and treatments interacted to significantly affect SM. Sweetgum produced a lower SM in all treatments, and the water treatment consistently reduced SM. The species and treatment factors acted independently of one another with respect to ML. Sweetgum lost significantly more mass than the other species, likely because of corresponding reductions in holocellulose. An acid treatment produced the greatest ML.