FTIR Characterization of Copper Ethanolamine—Wood Interaction for Wood Preservation

The interaction of copper ethanolamine (Cu-EA) preservative and wood components was studied by using Fourier transform infrared spectroscopy (FTIR). In Cu-EA treated wood, significant reduction was noticed on the band attributed to carbonyl vibration from carboxylic groups at 1735 ± 5 cm−1 and an increase in band intensity was obtained from carbonyl in carboxylate at 1595 ± 5 cm−1. The same observation was made in Cu-EA treated holocellulose. Cu-EA treated lignin resulted in a reduction in the aromatic ester band at 1710 ± 5 cm−1 and an increase in carbonyl from carboxylate at 1595 ± 5 cm−1. Bands at 1370 cm−1 and 1221 cm−1, assigned to phenolic hydroxyl groups, exhibited a decrease in intensity after the treatment. From these data, it is concluded that Cu-EA interacts with carboxylic groups, phenolic hydroxyl groups and ester groups from lignin to form copper carboxylate and phenolate complexes.