Wood modification with phenol urea formaldehyde (PUF) resin: the influence of wood species selection on the dimensional stability

Abstract Wood modification is an excellent way to improve material properties, prolong service life, and pave the for new applications timber in built environment. The aim of this study establish influence wood species process with phenol urea formaldehyde resin. Seven hardwoods four softwoods were compared identical treatment. Since main variable, provides a clear insight as its on modification—something not previously investigated. Small blocks all eleven impregnated low-molecular weight resin subsequently heat-cured at 150 °C. Mass dimensions specimens carefully monitored throughout three cycles oven-drying water-soaking determine anti-swelling efficiency, bulking coefficient, swelling coefficient. results showed relationship between density, bulking-, coefficients. Beyond well-known it was observed that similar density (e.g., lime sycamore) had significantly different coefficients efficiencies. Reasons these differences, which are independent discussed. soaking solution analysed nature leached substances showing correlation amount leachate UV-absorbance (272 nm) solution.