Proceedings Mass Timber Research Workshop 2015, USDA Forest Products Laboratory Madison, Wisconsin, USA November 3-4, 2015.

摘要

Protecting wood products from bio-deterioration has been a dynamic area of research in the past decade with an emphasis on the development of non-arsenical wood preservatives. Naturally occurring cellulose nanomaterials that are reported to have unique chemical properties, high strength, and stiffness were evaluated for the potential to improve durability of wood either as a stand-alone treatment or in combination with a cationic biocide. In this study, benzalkonium chloride (ADBAC) was selected as a biocidal counter-cation for the sulfate ester on cellulose nanocrystals (CNC). In a two-step pressure treatment, specimens of southern pine were impregnated with CNC or ADBAC to form a CNC/ADBAC hybrid agglomerate within the wood. Cellulose nano-crystals penetrated wood in the CNC control and when CNC was the first step in a dual treatment with ADBAC. However, when ADBAC was the first step in a dual treatment with CNC or pre-mixed with CNC, the agglomerated ADBAC/CNC could not penetrate wood and gelled on the wood surface. Biological and chemical analysis of wood treated with the CNC/ADBAC hybrid revealed that CNC provided no additional resistance to fungal colonization, termite attack, or chemical leaching when agglomerated to ADBAC in wood. Analysis of modulus of elasticity, modulus of rupture, work to maximum load, and mass loss during combustion showed no change in the physical properties from the addition of CNC to wood impregnated with the CNC/ADBAC hybrid treatment. While results of this study did show penetration of CNC into southern pine and leach-resistant binding of CNC to ADBAC, neither treatment of southern pine with CNC nor the addition of CNC to ADBAC in a dual treatment improved the biological, chemical, or physical durability properties of the wood.