Characterization of Merbau Extractives as a Potential Wood-Impregnating Material

Abstract

This study aimed to investigate the major content of merbau extractives (ME) and their potential use as an impregnating material for low-quality timber. Extraction was done by maceration with ethanol, ethyl-acetate, and hot-water. Physico-chemical, phyto-chemical, UV-visible, and infrared spectroscopy, as well as py-GCMS analysis were then performed on dried extract. The results showed that organic solvent extractions resulted in much higher yields, by 12.50% than that of hot water (1.10%). The merbau extractives liquid obtained had a low acidity, with a pH ranging from 5 to 6, which is typical of phenolic compounds. Flavonoids and phenolics were found as the major compounds. UV-vis spectra showed that ME (λ=279 nm) consists of conjugated or aromatic systems, similar to standard resorcinol, which was used as the reference (λ=274 nm). The FTIR spectra showed the absorption bands at 3369 cm-1 that represent the functional group of hydroxyl (OH) bonds, and 1619 and 1510 cm-1, representing the aromatic ring (C=C), which could be associated with resorcinol. The Py-GCMS showed that ME is predominated by resorcinol (C6H6O2) with a 79% concentration. The ME could be potentially used for producing phenolic/resorcinolic resin through polymerization, which could be applied for wood impregnation.