Forests and Forest Product Journal

Reducing Hygroscopicity of Triplochiton scleroxylon K. Schum. by Thermal Modification

By: Adebawo F. G.;  Adegoke O. A.;  Olaoye K. O.;  Adelusi E. A.;  

Abstract:

The thermal modification of wood is a potential alternative method for improving wood dimensional stability. However, during thermal modification, morphological changes occur within the cell wall structure, and these confer different properties to the wood. This study investigated the effects of the thermal modification process on reducing hygroscopicity of Triplochiton scleroxylon wood in terms of water absorption (WA), volumetric swelling (VS), water repellent efficiency (WRE) and anti-swelling efficiency (ASE). Three different temperatures (140 °C, 170 °C and 200 °C) at a varying duration of 3 h, 6 h and 12 h were considered for the thermal modification process. T. scleroxylon wood modified at 200 °C had the lowest WA of 41.99% and 78.25% after 24 h and 168h respectively among all the modified samples while untreated samples had the highest WA of 59.38% and 114.16% after 24 h and 168h respectively. Heat-treated samples had lower VS between 5.47- 8.90% after 168 h when compared with the untreated samples with 14.89%. WRE and ASE values also increase considerably with an increase in treatment temperature. This has shown improvement in the physical properties of Triplochiton scleroxylon making it suitable for outdoor purposes as a result of a reduction in the hygroscopicity of the wood after thermal treatment.

Keywords:  Thermal modification; water absorption; swelling; Triplochiton scleroxylon; Water Repellent Efficiency

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