Changes in Chemical Composition of Betung Bamboo (Dendrocalamus asper) after Alkali Immersion Treatment under Various Immersion Times

Abstract

This research aimed to analyze the change in chemical composition of the betung bamboo (Dendrocalamus asper) strands after alkali immersion treatment under various immersion times. The bamboo culms were converted into strands with the target length, width, and thickness of 70, 25, and 0.5 mm, respectively. Strands were alkali immersion-treated with 1% NaOH solution for 1, 2, and 3 h. Preparation of powder for chemical component analysis refers to the Technical Association of the Pulp and Paper Industry (TAPPI) standard T 264 cm-07 regarding the preparation of wood test samples for chemical analysis. Structural and non-structural bamboo strand chemical components such as holocellulose, alpha-cellulose, hemicellulose, klason lignin, and extractives were analyzed. The results showed that alkali immersion treatment decreased the hemicellulose content from 21.55% before treatment to 20.30% after 3 h immersion. Thus, it changed the holocellulose and alpha-cellulose composition. Alkali immersion treatment also changed the extractive substances dissolved in cold water, hot water, 1% NaOH, and ethanol-benzene solution. The decrease in hemicellulose, molecular weight lignin, and extractive substances would be beneficial for bamboo-oriented strand board manufacture to improve strand adhesion, dimensional stability, mechanical properties, and durability against biological agents attack. Keywords: alkali immersion times, alkali immersion treatment, bamboo, chemical components, pre-treatment

Physical and Mechanical Properties of Bamboo Oriented Strand Board Prepared fromAlkali-Immersed Strands

“…This phenomenon was also supported by previous research that alkali-immersed removed non-cellulosic materials and enhanced wettability (Doczekalska et al, 2014;Wang et al, 2018;Zhang et al, 2015). Murda et al (2022) reported that 1% sodium hydroxide immersion treatment for 1 -3 hours signi cantly decreased the level of betung bamboo extractives. Our previous research showed that the decrease in extractive substances signi cantly a ects the increase in adhesion quality (Fatrawana et al, 2019;Maulana et al, 2017;Maulana et al, 2019).…”

Durability to Natural Weathering of Methylene Diphenyl Diisocyanate-Bonded Bamboo Oriented Strand Board

“…Several species of bamboo such as andong (Gigantochloa verticillata), ampel (Bambusa vulgaris), and betung (Dendrocalamus asper), have been investigated for their feasibility for developing BOSB. Among these, betung bamboo has evident to show satisfied physical, mechanical, and wettability properties, and it is compatible for BOSB production (Baiti et al 2021b;Febrianto et al 2012Febrianto et al , 2015Mangurai et al 2022;Maulana et al 2019;Murda et al 2022a).…”

“…However, the large amount of extractive content in bamboo has a negative effect on bonding quality, which avoids the adhesive penetration process in bamboo-oriented strand board (BOSB) production (Fatrawana et al 2019;Murda et al 2018Murda et al , 2022a. The extractive content prevents the adhesive from spreading and entering the cell wall, influencing the overall quality of BOSB.…”