Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard

Bark from trees is considered a worthless raw material. However, this resource could be economically beneficial if utilized efficiently due to its rich chemical compounds. Employing bark particles without mixing other fibres minimised formaldehyde emissions from the particleboards meanwhile lignin e...

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Main Author: Rafidah Md Salim
Format: Thesis
Language:English
English
Published: 2023
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spelling my-ums-ep.390412024-07-04T06:19:58Z Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard 2023 Rafidah Md Salim TS920-937 Chemical processing of wood Bark from trees is considered a worthless raw material. However, this resource could be economically beneficial if utilized efficiently due to its rich chemical compounds. Employing bark particles without mixing other fibres minimised formaldehyde emissions from the particleboards meanwhile lignin extracted from bark used as an adhesive in bark particleboard can maximize the use of biomass waste, be cost effective, and be environmentally friendly. Utilizing appropriate particle sizes could improve the physical and mechanical qualities bark particleboard. In this study, Leucaena leucocephala stem bark that was eleven years old was examined for its chemical composition and usage. The chemical compositions (extractive, cellulose, and lignin) were analysis using FTIR spectroscopy. In the second section, the properties of particleboards made from coarse (2.5 to 12.0 mm), medium (1.0 to 2.5 mm), and fine (0.2 to 1.0 mm) Leucaena leucocephala bark particles bonded with urea formaldehyde adhesives were evaluated and in the final stage, lignin extracted from bark was used as an adhesive in bark particleboard at different particle sizes. The results found that the bark of L. leucocephala has a pH value of 6.04 and that the solubility of the bark in 1% NaOH alkali is the highest (41.36%) compared to the solubility in hot water (14.45%) and cold water (14.36%), while the chemical composition of the bark of L. leucocephala was ash (15.76%); extractives (8.39%); cellulose (29.19%) and lignin (38.24%). Results from FTIR analysis revealed that aromatic functional groups were mainly found in the extractive, while water, carbonyl and ether were the dominant groups in cellulose, and methyl, methylene, carbonyl, and carboxyl groups were enriched in lignin. The varying particle sizes had a significant impact on bark particleboard bonded with Urea formaldehyde (UF) adhesives which fine particles (0.2 to 1.0 mm) offered excellent physical properties for moisture content and dimensional stability, while coarse particles possessed good mechanical properties such as density, modulus of elasticity (MOE), modulus of rupture (MOR), and internal bonding (IB). The findings showed that lignin adhesive particleboard works more consistently than UF adhesive particleboard in an air-dry environment, but UF adhesive particleboard exhibits better resistance to water in wet situations. Compared to UF adhesive particleboard, lignin adhesive particleboard is more elastic and ruptures. The thickness swelling decreases in air-dry conditions, but it increases in wet situations as the particle size increases. Bark particleboard has superior strength when the particles used in its production are finer. In MOE, MOR, and IB, fine particles fared best. 2023 Thesis https://eprints.ums.edu.my/id/eprint/39041/ https://eprints.ums.edu.my/id/eprint/39041/1/24%20PAGES.pdf text en public https://eprints.ums.edu.my/id/eprint/39041/2/FULLTEXT.pdf text en validuser dphil doctoral Universiti Malaysia Sabah Faculty Of Science And Natural Resources
institution Universiti Malaysia Sabah
collection UMS Institutional Repository
language English
English
topic TS920-937 Chemical processing of wood
spellingShingle TS920-937 Chemical processing of wood
Rafidah Md Salim
Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard
description Bark from trees is considered a worthless raw material. However, this resource could be economically beneficial if utilized efficiently due to its rich chemical compounds. Employing bark particles without mixing other fibres minimised formaldehyde emissions from the particleboards meanwhile lignin extracted from bark used as an adhesive in bark particleboard can maximize the use of biomass waste, be cost effective, and be environmentally friendly. Utilizing appropriate particle sizes could improve the physical and mechanical qualities bark particleboard. In this study, Leucaena leucocephala stem bark that was eleven years old was examined for its chemical composition and usage. The chemical compositions (extractive, cellulose, and lignin) were analysis using FTIR spectroscopy. In the second section, the properties of particleboards made from coarse (2.5 to 12.0 mm), medium (1.0 to 2.5 mm), and fine (0.2 to 1.0 mm) Leucaena leucocephala bark particles bonded with urea formaldehyde adhesives were evaluated and in the final stage, lignin extracted from bark was used as an adhesive in bark particleboard at different particle sizes. The results found that the bark of L. leucocephala has a pH value of 6.04 and that the solubility of the bark in 1% NaOH alkali is the highest (41.36%) compared to the solubility in hot water (14.45%) and cold water (14.36%), while the chemical composition of the bark of L. leucocephala was ash (15.76%); extractives (8.39%); cellulose (29.19%) and lignin (38.24%). Results from FTIR analysis revealed that aromatic functional groups were mainly found in the extractive, while water, carbonyl and ether were the dominant groups in cellulose, and methyl, methylene, carbonyl, and carboxyl groups were enriched in lignin. The varying particle sizes had a significant impact on bark particleboard bonded with Urea formaldehyde (UF) adhesives which fine particles (0.2 to 1.0 mm) offered excellent physical properties for moisture content and dimensional stability, while coarse particles possessed good mechanical properties such as density, modulus of elasticity (MOE), modulus of rupture (MOR), and internal bonding (IB). The findings showed that lignin adhesive particleboard works more consistently than UF adhesive particleboard in an air-dry environment, but UF adhesive particleboard exhibits better resistance to water in wet situations. Compared to UF adhesive particleboard, lignin adhesive particleboard is more elastic and ruptures. The thickness swelling decreases in air-dry conditions, but it increases in wet situations as the particle size increases. Bark particleboard has superior strength when the particles used in its production are finer. In MOE, MOR, and IB, fine particles fared best.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Rafidah Md Salim
author_facet Rafidah Md Salim
author_sort Rafidah Md Salim
title Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard
title_short Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard
title_full Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard
title_fullStr Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard
title_full_unstemmed Properties of leucaena leucocephala Lam. Bark as lignin adhesive and particleboard
title_sort properties of leucaena leucocephala lam. bark as lignin adhesive and particleboard
granting_institution Universiti Malaysia Sabah
granting_department Faculty Of Science And Natural Resources
publishDate 2023
url https://eprints.ums.edu.my/id/eprint/39041/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/39041/2/FULLTEXT.pdf
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