Physicochemical properties of lignocellulosic biofibres from South Eastern Nigeria: Their suitability for biocomposite technology

Abstract

Five plant raw materials collected from South Eastern part of Nigeria were used for biofibre extraction and analysis to assess their suitability for biocomposite production. Lignocellulosic biofibres were extracted from young stems of Adenia lobata, Ampelocissus leonensis, Cissus palmatifida, Morinda morindoides and Urena lobata through natural water retting process for a period of 14 - 16 days and the resulting fibres were uniform with almost flat or circular cross sections. Phytochemical contents and extractives were determined on the untreated and treated fibres respectively. The %w/w cellulose contents of the pretreated biofibres were found to be 48.97± 1.33% for A. leonensis and 43.22±0.95% for A. lobata. The cellulose content of M. morindoides and C. palmitifida were found to be 55.76±1.40% and 55.20±1.59%, respectively. In all the plants studied, U. lobata had the greatest %w/w cellulose content of 58.94±1.05% while A. lobata had the least cellulose content of 43.22±0.95%. Estimation of %w/w hemicellulose contents showed A. leonensis to be 21.22±0.89% whilst the hemicelluloses content in A. lobata and U. lobata were observed to be 18.22±2.18% and 12.38±0.33% in that order. Lower hemicelluloses contents were obtained in C. palmitifida and M. morindoides as 10.32±1.27, 9.32±0.58 and 8.62±1.67%, respectively. The klason lignin contents were found to be 31.33±1.05% for C. palmitifida, 31.22±0.97% for M. morindoides, 28.22 ± 1.96% for A. lobata, and 24.91±0.61% for A. leonensis. The lignin content of U. lobata was found to be the least at 22.26±0.55%. Acid soluble lignin (ASL) content was greater in A. lobata (2.17±0.08%) while A. leonensis had the least value of 1.74±0.34%. ASL-derived products (vanillin, p-coumaric acid and ferulic acid) ranged between 0.50±0.12% and 1.41±0.02% for vanillin; 0.03± 0.02% and 0.65±0.14% for p-coumaric acid; and ferulic acid was only detected in A. leonensis as 0.41±0.11%. The mechanical properties of most fibres used in this study are comparable to those of other biofibres already used in manufacturing and can even match those of some synthetic fibres. Results obtained revealed that fibres used in this study had comparable properties with those already established for manufacturing in biofibre industries.

Keywords: Biofibre, biocomposite, cellulose, lignin, hemicelluloses.

African Journal of Biotechnology, Vol 13(20), 2050-2057