The effect of acetylation on hybrid poplar after artificial weathering

The effect of acetylation on weathering resistance of a hybrid poplar (Pacific Albus®) was studied by colour change evaluation, mechanical tests, FT-IR spectroscopy and moisture absorption measurements. The acetylation process was performed without any pre-treatment and it was verified by means of weight percentage gain and FT-IR spectroscopy: the average weight percentage gain was 14.4 ±0.6% and the band areas at 1370 and 1740 cm-1 increased about 50% compared to unmodified wood. It was also demonstrated that acetylation process increased mechanical performance and reduced wood moisture absorption. Unmodified and acetylated wood samples were artificially weathered with a Xenon-arc lamp up to 400 h. The mechanical properties of both acetylated and untreated wood showed the same trend, but acetylated samples exhibited higher stiffness, strength and elongation at break. The outcomes demonstrated that acetylated samples were more stable to degradation mechanisms induced by artificial weathering.