Physical-Mechanical Properties of Heartwood and Sapwood in Toona sp. Wood (Toona ciliata M. Roem.) Before and After Accelerated Aging Treatment

The differences of physical-mechanical properties in heartwood and sapwood of Toona sp. wood (Toona ciliata M. Roem.) were compared before and after an accelerated aging treatment, which was conducted in accordance with ASTM (American Society for Testing and Materials) standards. The results revealed that the physical-mechanical properties of heartwood were better than those of sapwood. The accelerated aging treatment weakened the physical-mechanical properties of the wood samples. During the aging treatment, the carbohydrates in the cell wall, including cellulose and hemicellulose, were depolymerized; as such, the crystallinity of cellulose was decreased by aging. The depolymerization of carbohydrates and the reduction of crystalline contributed to decreasing the physical-mechanical properties of the wood samples.