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Acetylation of tropical hardwood species from forest plantations in Costa Rica: an FTIR spectroscopic analysis

Acetylation of tropical hardwood species from forest plantations in Costa Rica: an FTIR spectroscopic analysis

Authors :
Johanna Gaitán-Alvarez
Alexander Berrocal
George I. Mantanis
Róger Moya
Fabio Araya
Source :
Journal of Wood Science, Vol 66, Iss 1, Pp 1-10 (2020)
Publication Year :
2020
Publisher :
SpringerOpen, 2020.

Abstract

Abstract Acetylation of softwoods has been largely investigated to increase the dimensional stability and biological resistance of wood. However, the knowledge of this technology has not been applied to tropical hardwood species up to date. The objective of this work was to study the effect of acetylation on nine tropical hardwood species, from forest plantations in Costa Rica, by applying acetic anhydride in three different treatment times (1 h, 2.5 h, 4 h), as well as to evaluate this by Fourier-Transform Infrared Spectroscopy (FTIR). Results showed that weight percentage gain (WPG) of wood varied from 2.2 to 16.8%, with Vochysia ferruginea species showing the highest WPG, and Gmelina arborea and Tectona grandis species exhibiting the lowest WPGs. Tropical woods such as Enterolobium cyclocarpum, Hieronyma alchorneoides and Samanea saman exhibited statistical differences among treatment times, whereas the rest of the species studied showed no significant differences. In general, the most effective acetylation time was 2.5 h for all the species. The ratio of intensity (RI) from the FTIR spectra was greater at the 1732 cm−1, 1372 cm−1 and 1228 cm−1 peaks for all tropical species, associated with lignin. A good correlation between the RI of those peaks and WPG was found; the same was also found between all RIs and each other. Meanwhile, RI associated to the hemicelluloses and lignin (1592 cm−1 and 1034 cm−1 peaks, respectively) showed no correlation with WPG, nor between each other or with the other RIs. Furthermore, it was suggested that RI at 1732 cm−1 (associated to acetyl groups C=O) can be considered as a reliable indicator of the degree of acetylation for tropical hardwood species. Finally, it was observed that tropical hardwoods having more suitable anatomical features, like larger vessel diameter, higher ray width and frequency, and lesser deposits such as gums and tyloses in the vessels, resulted in significantly higher WPGs.

Details

Language :
English
ISSN :
14350211 and 16114663
Volume :
66
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Journal of Wood Science
Publication Type :
Academic Journal
Accession number :
edsdoj.153b38caf42079fbba29b5fd5ec2f
Document Type :
article
Full Text :
https://doi.org/10.1186/s10086-020-01898-9