FTIR examination of preservative retention in beech wood (Fagus sylvatica L.)
A method of FTIR examination of preservative retention in beech wood structure was developed. Beech wood samples of different preservative content were prepared using low pressure preservation process in laboratory conditions. Then samples were homogenized in a laboratory mill and measurements were performed using FTIR spectrometer with attenuated total reflectance unit. Pure preservative was also measured and from its spectrum 1,555 cm−1 absorption band was chosen as the characteristic for preservative. 1,027 and 1,370 cm−1 were absorption bands characteristic for wood which were chosen as reference peaks. Values of two absorbance ratios, A1,555/A1,027 and A1,555/A1,370 were correlated with the preservative content in particular samples. Correlation coefficients were 0.8390 and 0.8313, respectively.
FTIR Characterization of Copper Ethanolamine—Wood Interaction for Wood Preservation
Summary 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.
Sorption of Copper by Wood Constituents
Belford, Myers and Preston1 have directed attention to the fact that cellulose and wood absorb copper ions and that they appear to be regularly spaced on a grid pattern not corresponding to the unit cell of cellulose. Bayley and Rose2 consider that α-cellulose has only a small cation binding power and that the complexes formed in wood consist of metal cations bound on the non-cellulosic constituents. Belford et al.3 observed that in, wood impregnated with preservatives containing copper-salts the middle lamella in particular stained very deeply with dithio-oxamide. In the work now reported the copper sorption of isolated wood constituents has been measured and the copper has been located in sections of treated wood by staining methods and electron microscopy.