Paper AS-TuP15
Impact of Surface Contaminants on ToF-SIMS analysis of Wood Polymer Composites (WPCs)

Tuesday, November 8, 2016, 6:30 pm, Room Hall D

Wood Polymer Composites (WPCs) are a promising material for outdoor applications, such as decking and marine structures, because they have improved properties over wood or plastic alone. WPCs also allow for the recycling of plastics and use of reclaimed wood. However, the use of WPCs poses questions regarding the breakdown and weathering of WPCs. The importance of the interface between wood and polymer components of the composite may make analysis with a chemical imaging technique such as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) advantageous. Due to the high surface sensitivity of ToF-SIMS, an understanding of the surface contaminants on WPCs is required. Contaminants on WPCs may arise from handling, storage, or from lubricants and other components used in the manufacturing process. As such, even new material surfaces can be considered contaminated. Therefore, the interiors of the WPCs were used as references, as the interior is an unhandled surface. The removal of contaminants by solvents (including purified water, isopropyl alcohol, and mixtures thereof) was evaluated to identify appropriate cleaning methods. Furthermore, it may be desirable to remove contaminants prior to or after controlled weathering experiments. Therefore, the chosen cleaning method was applied to previously weathered samples. Comparisons of ToF-SIMS spectra of the WPCs were performed using Principal Component Analysis (PCA) and Multivariate Curve Resolution (MCR). This work provides insight into how the surface and interior of the WPCs differ, how treatment with common solvents alter the obtained spectra, and how weathered surfaces appear with and without cleaning.