An Analysis of Impact of Furfurylation Treatments on the Physical and Mechanical Properties of Pterygota macrocarpa Wood

Abstract

Wood is an important structural material requiring treatments to improve its properties and resistance to biodeterioration agents; one of such is wood modification. Furfurylation is one of the chemical modifications of wood. It is based on wood impregnation with furfuryl alcohol and other agents (catalyst), followed by polymerization at an elevated temperature. The objective of this study was to assess the effect of furfuylation treatments on the physical and mechanical properties of Pterygota macrocarpa. Wood samples were collected from Pterygota macrocarpa tree longitudinally and transversely on which modification was carried out with furfuryl alcohol and catalyst (Maleic anhydride and Tartaric acid) at different proportions using a pressure impregnating equipment at a pressure of 4 bars and later cured at 150°C for 3 hours. Material preparations and testing were done according to the American Society for Testing Materials (ASTM). The data obtained were analysed using Statistical Package for Social Science (SPSS). Descriptive statistics of the properties measured were generated. The data were subjected to Analysis of Variance (ANOVA) and Duncan Multiple Range Test (DMRT) to determine the significant difference between various treatment and their interactions at 0.05 level of significance. Results of density for untreated P. macrocarpa wood ranged from 464.55 kg/m³ to 625.92 kg/m³ while modified P. 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 P. macrocarpa wood varied among the treatments which ranged from 5.70 to 15.26%. It was observed that the wood's dimensional stability (Anti-swelling efficiency) increased with furfurylation. Furthermore, the practical implications are the increase in the mechanical properties which varied among treatments. 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 4% level of tartaric acid recorded the highest values while compression parallel to grain ranged from 25.83 to 38.89 N/mm2 with 4% level of maleic anhydride having the highest value. For effective performance, 4% level of the catalysts can be used in the furfurylation process. The contributions of the research finding revealed that the inclusion of tartaric acid in the furfurylation process could serve as an alternative to maleic anhydride which is widely used. It is therefore recommended that further investigation should be carried out on the properties of furfurylated softwood and hardwood species.