ACETYLATION OF WOOD USING SUPERCRITICAL CARBON DIOXIDE

Abstract

This study investigated the effects of acetylation using supercritical carbon dioxide (CO₂) on dimensional stability of four wood species grown in Sri Lanka. Heartwood specimens of Paraserianthes falcata, Alstonia macrophylla, Pinus caribaea and Hevea brasiliensis were acetylated with acetic anhydride using supercritical CO₂ (120 °C, 10–12 MPa), and their dimensional stability was evaluated. Results showed that anti-swelling efficiency values of the wood species increased to over 60% after 8 hours of acetylation. In particular, A. macrophylla exhibited a relatively high anti-swelling efficiency. High anti-swelling efficiency of A. macrophylla was caused by the large swelling of this high specific gravity wood.