Lo, Ket Soon (2012) Influence of wood extractives from different extraction solvents on the colour changes and mechanical properties of acacia hybrid particleboard. Masters thesis, Universiti Malaysia Sabah.
Effect of wood extractives towards particleboard production was less emphasized by other researchers. The aim of this study was to determine wood extractives of Acacia hybrid, and evaluate colour changes and mechanical properties of particleboard made from Acacia hybrid. Acacia hybrid was divided into bark, sapwood and heartwood. Each portion had undergoing soxhlet extraction according to American Society for Testing and Materials Standard (ASTM) D1108-96, D1107- 96 and D1110-84 using different polarity solvents; hexane, methanol and hot water. The crude extract of each portion was analyzed to determine the chemical components of wood extractives from the extraction solvents. Wood extractives covered in this study were low molecular weight compounds; fatty acids, sterols, glycerides and steryl ester. Gas chromatography analysis was carried out for crude extract of hexane and methanol due to these volatile solvents. Crude extract of hot water was analyzed by High Performance Uquid Chromatography due to its non-volatility. Results shown that total extractives analyzed by Gas chromatography for methanol extract in heartwood was highest, 1.45 mg/g, followed by bark and sapwood of 1.39 mg/g and 0.89 mg/g respectively. For hot water extract, heartwood was found to have the most in total extractives, 1.83 mg/g, followed by bark 1.26 mg/g and sapwood, 0.82 mg/g. In term of physical property of colour changes, results shown that colour changes of lightness (L *) for wood powder was lightest by using methanol to extract bark, sapwood and heartwood that were, 50.25 for bark, 50.31 for sapwood and 41.57 for heartwood. In producing particleboard, larger amount of wood particles were extracted using the ratio of extraction on wood particle to solvent extraction; 1 g of wood particle to 10 ml of solvent for 6 hours of extraction period. Wood particles were glued using urea formaldehyde and the targeted density was 500 kg/m3 • Particleboards produced were tested on static bending and internal bonding according to ASTM Standard D1037-06a. Results shown that particleboard made from methanol extracted wood particle for sapwood and heartwood had a significant difference at p≤0.05 for static bending and internal bonding. Sapwood extracted by methanol was 0.5 times higher for both Modulus of Rupture (MaR) and Modulus of Elasicity (MOE) and 0.3 times higher for internal bonding as compared to control sapwood particleboard. Heartwood extracted by methanol was 2.0 times higher for MaR and MOE and 0.6 times higher for internal bonding compared to control heartwood particleboard. However, bark extracted by hexane was 0.4 times higher for MaR, 2.0 times for MOE and 0.3 times higher for internal bonding as compare to control bark.
|Item Type:||Thesis (Masters)|
|Uncontrolled Keywords:||Acacia hybrid, wood extractives, particleboard|
|Subjects:||S Agriculture > SD Forestry|
|Divisions:||SCHOOL > School of International Tropical Forestry|
|Deposited By:||IR Admin|
|Deposited On:||07 Oct 2015 16:09|
|Last Modified:||07 Oct 2015 16:09|
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