Characterization of Merbau Extractives as a Potential Wood-Impregnating Material

Abstract

aThis 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.

Molecular level comparison of water extractives of maple and oak with negative and positive ion ESI FT‐ICR mass spectrometry

“…For example, Malik and Santoso reported extraction efficiencies in the range of 0.7% to 6.7% for oily keruing wood samples using solutions of water and ethanol in various proportions. Malik et al reported that the extraction yield of merbau extractives were 12.45%, 12.56%, and 1.34% when 80% ethanol, 60% ethyl acetate, and hot water were used, respectively. The organic solvents increase the extractive efficiency due to the fact that their polar and nonpolar functional groups dissolve more complicated compounds, such as tannins, resins, wax, and gum.…”

“…The solvent choice should depend on the targeted extracted compounds and/or the purpose of the extraction. From a general environmental point of view, water is better than organic solvents, because it is relatively cheap, nontoxic, inflammable, and recyclable . As the primary purpose of this work was characterizing the water‐soluble materials in wood veneers, water was the best choice.…”

“…Besides cellulose, hemicellulose, and lignin as the main structure components of cell walls, wood contains other nonstructural substances known as extractives . Wood extractives may be extracted by water and/or organic solvents.…”

Mechanical characteristics of impregnated white Jabon wood ( Anthocephalus cadamba ) using merbau extractives and selected polymerised merbau extractives

“…The first (1) and the second (2) extracts were combined to make a concentrate (with the use of a rotary evaporator), which was freeze-dried to powder. The properties the ME have been thoroughly investigated by Malik et al (2016). Hot water was used as the solvent in this study because according to Kislik (2012), water is the best alternative for organic solvent.…”

“…This procedure was applied for the samples of the three impregnating solutions (ME, PME22 and PME33). After that, all specimens were drained and then put into a conditioning room until a constant weight was reached (Malik et al 2015, Malik et al 2016, Malik et al 2018. The moisture content of all tested samples was 12% to avoid -according to Rowell (1996) -a misleading or even invalid values if the samples were tested at different moisture levels.…”