Effect of Process Variables on the Composition of Chemically Modified Nauclea latifolia Wood Bark Fiber for Paper Production

The shortage of sustainable fiber sources in the chemical industry highlights the need for alternatives to synthetic fibers, which have been widely used for years. This study examined the effect of NaOH treatment on the chemical composition of a novel fiber obtained from Nauclea latifolia bark wood (NLWBF). The objective was to investigate the influence of NaOH concentration and soaking time on NLWBF. Soaking time and NaOH concentration were varied from 1.2 to 3.6 hours and 3.4 to 10.2 % w/v, respectively. After collection, the NLWBF was processed into powdered form and treated to remove impurities. Both modified and unmodified NLWBF samples at optimum treatment conditions were structurally analyzed using Fourier Transform Infrared Spectroscopy (FTIR) to identify the organic functional groups present. The initial cellulose (CL), hemicellulose (HM), and lignin (LN) contents of NLWBF were 36.83%, 29.71%, and 31.29%, respectively. After chemical modification, the maximum cellulose content of 69.06% was obtained at 3.6 hours and 6.8% w/v NaOH. The optimum hemicellulose content was 18.14%, recorded at 2.4 hours and 6.8% w/v. FTIR spectra revealed the presence of OH, –COOH, C=O, C–O, and C–O–C groups, with noticeable shifts after NaOH treatment, confirming chemical modification. These changes indicated a reduction in hemicellulose and lignin, thereby enhancing the cellulose content of NLWBF. The results demonstrate that NaOH-treated NLWBF, with its improved cellulose composition, holds strong potential as a sustainable raw material for industrial paper.