Study on physical properties and weathering resistance of wood modified by formaldehyde-based resins containing nano zinc oxide

The use of wood in outdoor applications causes problems such as dimensional change, weathering and biological degradation. In this study, poplar wood was modified by three types of amino resins (melamine, melamine-urea and urea formaldehyde resins) and nano Zinc oxide (0, 0.5 wt%). Then, the physical properties and weathering resistance of modified wood after six months natural weathering were measured. The results showed that the treatment of wood with amino resins reduced water absorption and improved dimensional stability of samples in which melamine formaldehyde resin had the best performance. Moreover, the addition of nano zinc oxide to the amino resins enhanced their performance in improving dimensional stability of samples. The results of the colorimetry and microscopic images indicate that the treating by melamine formaldehyde reduced the color changes and surface morphology of the samples, although the use of nano zinc oxide did not have a positive effect in this regard.