Effects of Borate Pretreatment on the Acidity and Colour Response of Wood to Heat Treatment

Abstract The effects of borate pre-treatment on the acidity and colour changes in wood during heat treatment were investigated. Borate pretreatment reduced the build-up of wood acid, which, commonly occurs during heat treatment. This therefore suggests prevention of degradation of the hemicelluloses. There was a decrease in colour intensity during the heat treatment of wood pre-treated with borate buffer. This results in the production of material darker in colour after heat treatment. However, heat treatment itself without borate impregnation does not have any appreciable effects on wood colour and this was thought to be an indication of the possibility of differences in the effects of heat treatment on wood colour in different wood species. Lost of colour however is by no means a limitation to the use of borate in mitigating the deleterious effects of heat treatment since the darker colour can serve as a boost to the aesthetic value of wood.

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