Color changes of wood from Pinus taeda and Schizolobium parahybum treated by in situ polymerization of methyl methacrylate using cross-linkers

The aim of this study was to evaluate the colorimetric properties of Pinus taeda and Schizolobium parahybum woods treated by in situ polymerization. The wood samples were impregnated in a vacuum/ pressure system and polymerized in an oven at 90°C for 10h, using benzoyl peroxide at 1,5wt% as the catalyst. The treatments were characterized using attenuated total reflectance infrared (ATRIR) spectroscopy and weight percentage gain (WPG). The color evaluation was performed using CIEL*a*b* concepts, specular gloss, and UV-Visible spectrophotometry. Treated woods showed increases in band intensity related to polymers (1730, 1460 and 1145 cm-1), and WPG ranged from39 to 164%, depending of the wood species and treatments. Lightness decreased, while the Chroma, gloss and the color coordinates increased. A darkening of the all treated samples was observed, and confirmed by the decrease in the reflectance intensity between 400 and 700 nm