Abstract:
Wood is a very important structural material with numerous advantages which makes it an indispensable engineering material. However, it is biodegradable, combustible, its properties changes with humidity fluctuations and is different for each structural direction. Over the years, there were developments in the area of wood modification. The development could be attributed to increased environmental concerns, demand for high and quality products and limited availability of tropical timber as a result of over-exploitation as well as to overcome the undesirable properties of wood. This study was aimed at increasing the service life of Pterygota macrocarpa wood through modification with furfuryl alcohol and catalyst (Maleic anhydride and Tartaric acid) at different proportions. Wood samples were collected from Pterygota macrocarpa tree longitudinally and transversely. Modification of wood was carried out using pressure impregnating equipment. Furfurylation was carried out in two stages (impregnation with chemicals at pressure of 4 bars and curing at 150°C for 3 hours). Results of density for Pterygota macrocarpa wood ranged from 464.55 Kg/m³ to 625.92 Kg/m³. Modified Pterygota macrocarpa wood has weight percent gain (WPG) and density increment (DI) due to furfurylation which ranged from 8.65 to 15.34% and 1.49 to 4.94% respectively. Effect of bulking coefficient (BC) on Pterygota macrocarpa wood varied among the treatments which ranged from 5.70 to 15.26%. It was observed that the dimensional stability (Anti-swelling efficiency) of Pterygota macrocarpa wood increased with furfurylation. Furthermore, there was increase in the mechanical properties of Pterygota macrocarpa wood which varied among treatment. Modulus of Elasticity ranged from 2098.27 to 3372.64 N/mm2, Modulus of Rupture ranged from 44.82 to 64.53 N/mm2 with treatment 4 (higher level of tartaric acid) with the highest values while compression parallel to grain ranged from 25.83 to 38.89 N/mm2 with treatment 2 (higher level of maleic anhydride)
having the highest value. Furfurylated Pterygota macrocarpa wood also showed greater resistance to fungal (Phenoracheate crysosporium) growth and decay with treatment 3 (lower level of tartaric acid) giving Pterygota macrocarpa wood higher resistance to fungal decay.
Regardless of the stem height and lateral positions of Pterygota macrocarpa wood, furfurylation catalyzed with different catalyst has considerable increase in the physical and mechanical properties of the wood, as well as its resistance to fungal decay. For effective performance, higher level of the catalyst can be used in the furfurylation process. The result of this research revealed that tartaric acid can likewise be used in furfurylation process as the maleic anhydride which is currently widely accepted.
