• Ruth Anayimi Lafia-Araga Department of Chemistry, School of Physical Sciences, Federal University of Technology, Minna. NG 920001 Nigeria.
  • Blessing A. C. Enwere Department of Chemistry, Federal College of Education, Zuba, Federal Capital Territory, Abuja Nigeria.
  • Mohammed A. T. Suleiman Department of Chemistry, School of Physical Sciences, Federal University of Technology, Minna. NG 920001 Nigeria.
  • Stephen S Ochigbo Department of Chemistry, School of Physical Sciences, Federal University of Technology, Minna. NG 920001 Nigeria.


Gmelina arborea sawdust was chemically modified using 4% and 8% concentrations of NaOH solution for 30 and 90 minutes soaking times. The influence of this modification on the chemical composition and thermal properties of samples were investigated. Chemical characterization of samples revealed that the percentage content of hemicellulose decreased from 24.5% in the unmodified sample to 20.8%, 17.6% and 15.2% in samples soaked in 4% NaOH solution for 90 minutes, 8% NaOH for 30 and 90 minutes respectively. The amount of lignin decreased from 25.0% in unmodified samples to 19.0% when the sample was treated with 8% NaOH for 90 minutes. A moisture content of 9.0% and 2.5% were recorded in unmodified and sample treated with 8% NaOH for 90 minutes respectively. However, the cellulose content increased from 38.1% in unmodified sample to 60.1% when the sample was treated with 8% NaOH for 90 minutes. The percentage weight loss increased as concentration and modification time increased. Functional groups analysis by Fourier Transform Infrared Spectroscopy (FTIR) showed evidence of reduction in OH and removal of C=O groups associated with the wood polymers after chemical modification. Thermogravimetric analysis revealed that samples treated with 4% NaOH for 90 minutes presented the highest onset and peak degradation temperatures of 274.0°C and 372.1°C respectively. From these results, it can be concluded that modification with 4% NaOH solution for 90 minutes imparted a significant improvement on the thermal stability of Gmelina arborea sawdust.


Akinrinola, F. S., Darvell, L. I., Jones, J. M., Williams, A., & Fuwape, J. A. (2014). Characterization of selected Nigerian biomass for combustion and pyrolysis applications. Energy and Fuels, 28, 3821-3832.
ASTM D1105-96 (2013), Standard test method for preparation of extractive-free wood, ASTM International, West Conshohocken, PA,
ASTM D1106-96(2013), Standard test method for acid-insoluble lignin in wood, ASTM International, West Conshohocken, PA,
ASTM D4442-16 (2016), Standard test methods for direct moisture content measurement of wood and wood-based materials, ASTM International, West Conshohocken, PA, ,
ASTM E1755-01(2015), Standard test method for ash in biomass, ASTM International, West Conshohocken, PA,
Bodîrlău, R., & Teacă, C. A. (2007). Fourier transforms infrared spectroscopy and thermal analysis of lignocelluloses fillers modified with organic anhydrides. Romanian Journal of Applied Physics, 54, 93-104.
Deepa, B., Abraham, E., Cherian, B. M., Bismarck, A., Blaker, J. J., Pothan, L. A., Leao, A. L., & Kottaisamy, M. (2011). Structure, morphology and thermal characteristics of banana nanofiber obtained by steam explosion. Bioresource Technology, 102, 1988-1997.
Esteves, B & Pereira, H. M.(2008). Wood modification by heat treatment: A review. BioResources, 4, 370-404.
Fa´bio, T., Thais, H. D. S., & Kestur, G. S. (2007). Studies on lignocellulosics fibre of Brazil. Part II: Morphology and properties of Brazilian coconut fibre. Composites: Part A, 38, 1710–1721.
Gassan, J & Bledzki, A. K. (1999). Alkali treatment of jute fibres: Relationship between structure and mechanical properties. Journal of Applied Polymer Science. 71, 623-629.
Hakkou, M., Pétrissans, M., Bakali, I., Gérardin, P., & Zoulalian, A. (2005). Wettability changes and mass loss during heat treatment of wood. Holzforschung, 59, 35-37.
Jayabal, S., Sathiyamurthy, S., Loganathan, K. T., & Kalyanasundaram, S. (2012). Effect of soaking time and concentration of NaOH solution on mechanical properties of coir polyester composites. Bulletin of Material Science, Indian Academy of Sciences, 35, 567–574.
Kalia S., Kaith, B. S., & Kaur, I (2009). Pretreatments of natural fibres and their application as reinforcing material in polymer composites - A review. Polymer Engineering & Science, 49, 1253-1272.
Kallakas, H., Shamim, M. A., Olutubo, T., Poltimäe, T., Krumme, A., & Kers, J. (2015). Effect of chemical modification of wood flour on the mechanical properties of wood-plastic composites. Agronomy Research, 13, 639–653.
Kelly, C. C., Carvalho, D. R., Mulinari, H. J. C., Maria, O. H. C., & Voorwald, A. C. (2010). Chemical modification effect on the mechanical properties of Hips/Coconut fiber composites. Bioresource Technology, 5, 1143-1155.
Korkut, S., & Kocaefe, D. (2009). Effect of heat treatment on wood properties. Duzce University Journal of Forestry, 5, 11-34.
Kotalainen, R, Alen, R & Arpiainen, V. (1999) Changes in the chemical composition of Norway Spruce (Picea abies) at 160°C–260°C under air and nitrogen atmospheres. Paper Timber; 81, 384–388.
Lafia-Araga, R. A., Hassan, A., Yahya, R., Abd. Rahman, N., Hornsby, P. R & Heidarian, J (2012). Thermal and mechanical properties of treated and untreated Red Balau (Shorea dipterocarpaceae)/LDPE composites. Journal of Reinforced Plastics and Composites, 31, 215-224.
Liu, W., Mohanty, A. K., Drzal, L. T., Askel, P., & Misra, M. (2004). Effects of alkali treatment on the structure, morphology and thermal properties of native grass fibers as reinforcements for polymer matrix composites. Journal of Materials Sciences, 39, 1051-1054.
Manna, S., Saha, P., Chowdhury, S., & Thomas, S (2017). Alkali treatment to improve physical, mechanical and chemical properties of lignocellulosic natural fibers for use in various applications. In: Kuila, A & Sharma, V (eds.) Lignocellulosic biomass production and industrial applications. John Wiley & Sons.
Mansour, R., Hocine, O., Abdellatif, I., & Noureddine, B. (2011). Effect of chemical treatment on flexure properties of natural fiber-reinforced polyester composite. Procedia Engineering, 56, 2092-2097.
Maya, J. J., & Rajesh, D. A. (2008). Recent development in chemical modification and characterization of natural fiber-reinforced composites. Polymer Composites, 29, 187-207.
Mohammed, A. A., & Kesava, R. V. (2014). Thermal characterization of Neem and Cork wood polyacrylonitrile composites. Global Journal of Research in Mechanical and Mechanics Engineering, 14, 234-245.
Okoroigwe, E. (2015). Combustion analysis and devolatilisation kinetics of gmelina, mango, neem and tropical almond woods under oxidative condition. International Journal of Renewable Energy Research, 5, 1024-1033.
Olakanmi E.O, Ogunesan, E.A., Vunai, E, Lafia-Araga R.A, Doyoyo M & Meijboom R (2015). Mechanism of fiber/matrix bond and properties of wood polymer composites produced from alkaline treated Daniella oliveri wood flour. Polymer Composites, DOI 10.1002/pc.23460.
Reddy, H. K., Reddy, M. R., Ramesh, M., Krishnudu, M. D., Reddy, M. B., & Rao, R. H. (2019): Impact of alkali treatment on characterization of tapsi (sterculia urens) natural bark fiber reinforced polymer composites. Journal of Natural Fibers, DOI: 10.1080/15440478.2019.1623747.
Rowell R. M., Pettersen R., Han J. S., Rowell J. S & A. Tshabalala M. (2005). Cell wall chemistry. In: R. M. Rowell; Editor. Handbook of wood chemistry and wood composites. Boca Raton: CRC Press,. 473.
Rowell, R. M. (2006). Acetylation of wood: A journey from analytical technique to commercial reality. Forest Product Journal, 56, 4–12.
Shayesteh, H., & Gregory, D. S. (2015). Natural fiber reinforced polyester composites: A literature review. Journal of Reinforced Plastics and Composites, 35, 23-29.
Sultana, S., Nur, H. P., Saha, T., & Saha, M. (2012). Fabrication of raw and oxidized sawdust reinforced low density polyethylene (LDPE) composites and investigation of their physico-mechanical properties. Bangladesh Journal of Scientific and Industrial Research, 47, 365-372.
Vinod, A., Vijay R., Singaravelu, D. L., Sanjay, M. R., Siengchin, S., & Moure, M. M (2019). Characterization of untreated and alkali treated natural fibers extracted from the stem of catharanthus roseus. Material Research Express, DOI:10.1088/2053-1591/ab22d9.
Wu, C-M 1., Lai, W-Y., & Wang, C-Y (2016). Effects of surface modification on the mechanical properties of flax/polypropylene composites. Materials, 9, 314:1-11.
Xiaoli, G., Lan, S., Guozhen, L., Chaoqun, Y., Chun, K. C., & Jianfeng, Y. (2015). Chemical modification of poplar wood in gas and liquid-phase acetylation. Wood Research, 60, 247-254
Zhu, J., Brington, J., Zhu, H., & Abhyankar, H. (2015). Effect of alkali, esterification and silane surface treatments on properties of flax fibers. Journal of Scientific Research & Reports, 4, 1-11.
How to Cite
LAFIA-ARAGA, Ruth Anayimi et al. THERMAL DEGRADATION PROFILE OF CHEMICALLY MODIFIED WOOD SAWDUST. International STEM Journal, [S.l.], v. 1, n. 1, p. 47-58, dec. 2020. Available at: <>. Date accessed: 23 jan. 2021.

Most read articles by the same author(s)

Obs.: This plugin requires at least one statistics/report plugin to be enabled. If your statistics plugins provide more than one metric then please also select a main metric on the admin's site settings page and/or on the journal manager's settings pages.