Owoyemi, J.M.

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One of the major problems of wood in service is dimensional stability caused by absorption of moisture from humid environment. Recent effort has been on using non-chemical treatment to enhance wood serviceable life. Therefore, this study examined the influence of thermal treatment on the physical and mechanical properties of Hevea braziliensis wood. The wood samples were selected from the top, middle and base of rubber trees, oven-dried to a moisture content of 12% before thermal modification in a muffle furnace at varying temperature of 160 ºC, 180 ºC and 200oC for 30, 60 and 90 minutes duration. Mean values for water absorption ranged from 54.55% (160°C for 30 min) to 49.34% (200°C for 90 min). The Modulus of Rupture values varied from 87.22N/mm2 at 160°C to 66.87N/mm2 at 200°C. Increase in treatment time from 30 minutes to 60 minutes caused a decrease in the MOR from 86.98N/mm2 at 30 minutes to 73.23N/mm2 at 60 minutes. There were significant difference in the results obtained with thermally treated wood at 200 ºC and 90 minutes with improvement in resistance of rubber wood to moisture and decrease in mechanical properties especially the modulus of rupture. The result showed that thermal treatment could improve the resistance of the wood to moisture absorption and enhanced mechanical properties of the treated wood. Keywords: Hygroscopicity, Moisture content, Anti swelling efficiency, bending strength, Density.