Deciphering the Interaction between Wood Components and Preservative Chemicals: A Comparison of Analytical Techniques

The durability of preservative-treated wood is highly dependent on the interaction of wood components (cellulose, hemicellulose, lignin, and extractives) with preservative chemicals. Wood preservatives are generally comprised of metal ions, commonly copper, chromium, and arsenic, with iron as a pigment. This work establishes methods to quantify interactions between preservative chemicals and main wood components, to aid efforts in formulation development that extend the weathering performance of wood. Analytical methods for isothermal titration calorimetry (ITC) and quartz crystal microbalance with dissipation monitoring (QCMD) were developed. Iron was found to interact with organosolv softwood lignin and beechwood glucuronoxylan, whereas copper, arsenic, and chromium were found to interact with the glucuronoxylan only. Additionally, the impact of alkaline copper quaternary(ACQ)-type preservative treatment on the degradation of wood structures by UV-A light was studied using Fourier transform infrared spectroscopy (FTIR) and the distribution of copper ions visualized using time-of-flight secondary ion mass spectrometry (ToF-SIMS).M.A.S