Influence of Thermal and Chemical Modification on the Physical and Mechanical Properties of Leucaena leucocephala Wood

This study examined the physical and mechanical properties of thermally and chemically modified Leucaena leucocephala wood. Sample planks were obtained from Akure and reduced to defect-free samples of 20 mm × 20 mm × 60 mm. Wood samples were oven dried to a constant weight at 103 ± 2°C and cooled in a desiccator before the thermal treatment. Heat treatment of wood was Carried out in a muffle furnace at 140, 160 and 180°C for 1hr and 2 hrs. Butyl Acetate was used for the chemical treatment. The dimensional stability, weight gain of the samples was measured with parameters such as volumetric swelling, percentage weight gain and water absorption.

The result of WA showed that there was a decrease with increased temperature and treatment time. At a treatment time of 2 hr, lower values of WA were obtained as compared to the control samples which are 22.65% at 160°C and 17.15% for 180°C. Volumetric swelling values of 5.87 and 5.56 at 160°C and 180°C were obtained during the experiment. The result of the experiment showed that the water absorption of the wood decreases at increasing temperature and treatment time but after prolonged soaking of wood in water thermally treated wood showed lower resistance to biodeterioration as compared to chemically treated wood.

Chemically modified wood showed increased MOR at 2 hrs treatment time (109.75 N/mm2) than thermally treated wood with MOR of 99.14 N/mm2 at 160°C and 48.76 N/mm2 at 180°C which makes them be more durable and can therefore be used for constructional purposes.