WOOD PROPERTIES OF NINE ACETYLATED TROPICAL HARDWOODS FROM FAST-GROWTH PLANTATIONS IN COSTA RICA
The treatment of acetylation on tropical woods is influenced by their different levels of permeability and how these affect the weight percentage gain (WPG) in acetylated wood. The objective of the current study was to identify the effect of acetylation on the thermal stability, color, physical properties, hygroscopic and dimensional stability, wetting rate, and durability of nine tropical species of woods used for the commercial reforestation in Costa Rica. Study results showed that WPG varied from 2.2% to 16.8%. Positive significant correlations were observed between WPG and pre-exponential factors in TGA analysis and two parameters of dimensional and hygroscopic stability, whereas a negative correlation was observed with water absorption. In species with a WPG of over 10% (Vochysia ferruginea, V. guatemalensis, Cordia alliodora, and Enterolobium cyclocarpum) the thermal stability, wetting rate, hygroscopic stability, and resistance to biological attack showed an increase while swelling, and water absorption decreased. For these species, the best behaviors were obtained with an acetylation time of 2.5 hours and WPG values of over 10%. The same properties of wood in species with a WPG under 5% were found to be less affected by the different acetylation times and showed little difference in relation to untreated wood. Finally, the analysis showed that the dimensional stability obtained was attributed to the reduction of the absorptive capacity of the acetylated wood.
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.