Phenol formaldehyde adhesives formulated for advanced X-ray imaging in wood-composite bondlines

摘要: A phenol formaldehyde (PF) adhesive was uniformly tagged with iodine such that it yielded sufficient X-ray computed tomography (XCT) gray-scale contrast for material segmentation in reconstructed wood-composite bondlines. Typically, untagged adhesives are organic and have a similar solid-state density as wood cell-walls, therefore cannot be segmented quantitatively XCT data. The iodinated PF development involved analysis comparison of three trial containing rubidium, bromine, or iodine. Adhesive tag efficacy measured terms absorption enhancement uniformity along the polymers. Cured density, element, concentration were each found to significantly impact results, which turn agreed theoretical attenuation predictions resin. Ion chromatography confirmed absence free iodide liquid prior bonding, fluorescence microscopy energy-dispersive spectroscopy (EDS) showed tags remained associated cured EDS results also demonstrated when agents simply mixed into resins, rather than attached polymer chains, they migrate independent penetrating during bonding. This then can cause complications quantitative analyses. consistent uniform contrast; its formulation could adjusted other viscosity molecular weight distribution, would affect penetration behavior.