WOOD RESEARCH Volume 67, Number 6, 2022
Nduduzo Khumalo, Samson Mohomane, Setumo V. Motloung, Lehlohonolo Koao, Malevu D. Thembinkosi, and Tshwafo E. Motaung

Effect of H2SO4/HCLO4 mixture on properties of sugarcane bagasse cellulose crystals

The main objective of the study was to investigate the effect of mixed acid concentration on the morphology, crystallinity and thermal properties of cellulose nanocrystals (CNCs). Acid hydrolysis using mixture of sulphuric (H2SO4) acid and perchloric (HClO4) acid was used to extract CNCs from sugarcane bagasse (SCB). The properties of the raw SCB, extracted cellulose, 45% H2SO4 hydrolysed CNCs, 45% H2SO4/HClO4 hydrolysed CNCs, 55% H2SO4/HClO4 hydrolysed CNCs and 65% H2SO4/HClO4 hydrolysed CNCs were analysed using Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The crystallinity of SCB was significantly increased after bleaching and acid hydrolysis. Acid hydrolysis using 55% H2SO4/HClO4 showed the highest crystallinity. The TGA results showed significant increase in thermal stability of 55% H2SO4/HClO4. The lowest thermal stability was observed with 45% H2SO4 hydrolysed CNCs. The order of thermal stability was raw SCB < extracted cellulose < 45% H2SO4 hydrolysed CNCs < 65% H2SO4/HClO4 hydrolysed CNCs < 45% H2SO4/HClO4 hydrolysed CNCs < 55% H2SO4/HClO4 hydrolysed CNCs. The SEM results showed fibre breakage for 65% H2SO4/HClO4 hydrolysed CNCs. The fibre breakage seemed to be acid concentration dependent.

WOOD RESEARCH Volume 62, Number 6, 2017
Samson M. Mohomane, Linda Z. Linganiso, Thuli Buthelezi, and Tshwafo E. Motaung

Effect of extraction period on properties of sugarcane bagasse and softwood chips cellulose

This work evaluates the extraction of sugarcane bagasse (SCB) and soft wood (SW) celluloses with alkali treatment followed by bleaching process using sodium chlorite at different time. The influence of extraction time (2 hrs and 4 hrs) on the thermal, crystallinity and morphological properties was investigated. The extracted celluloses were analysed by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The aromatic skeletal vibrations of lignin and hemicellulose confirmed the extraction of cellulose which varied extraction time. TGA analysis shows that the untreated SCB degrade earlier than their respective celluloses and the prolonged treatment affects the onset of main degradation. XRD results showed that extracted celluloses had greater crystallinity index, and was affected at prolonged time due to long range destruction of cellulose crystals. The SW revealed a complex behaviour due to the dominated lignin content as revealed from chemical composition analyses.

WOOD RESEARCH Volume 65, Number 5, 2020
Ana Laura Soler Cunha Buzo, Sergio Augusto Mello Silva, Vinicius Borges De Moura Aquino, Eduardo Chahud, Luiz Antonio Melgaço Nunes Branco, Diego Henrique De Almeida, André Luis Christoforo, João Paulo Boff Almeida, and Francisco Antonio Rocco Lahr

Addition of sugarcane bagasse for the production of particleboards bonded with urea-formaldehyde and polyurethane resins

The present study deals with a production of pine particleboards using the sugarcane bagasse content and using castor-oil based bicomponent polyurethane resin and urea-formaldehyde resin. The influence of incorporation of sugarcane bagasse on the physical and mechanical properties of the composites was evaluated. The particleboards were produced according Brazilian standard ABNT NBR 14810, but performance requirements have been analyzed using Brazilian and international standards, as well. Treatment 2, using PU resin, were considered the best treatment using pine residue and sugarcane bagasse, presenting physical properties values 60% lower and mechanical properties 65% higher on average when compared with panel without sugarcane bagasse, indicating the good performance of sugarcane incorporation and the possibility of its use on commercial purpose for thermal and acoustic insulation. The addition of sugarcane bagasse improved physical and mechanical properties of particleboards when compared to panels manufactured from pine wood particles only. Statistical analysis indicated that moisture content and bagasse content were significant, enhancing properties when compared with reference treatments.

WOOD RESEARCH Volume 64, Number 2, 2019
Linda Z. Linganiso, Thuli Buthelezi, and Tshwafo E. Motaung

A comparative study of sugarcane bagasse and soft wood

This article investigated properties of different lignocellulosic biomasses. Both acidified and non-acidified sodium chlorite were used to treat wood chips and sugar cane bagasse. Images were part of characterizations that included X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). Interestingly the results indicated that biomasses followed the similar crystallinity trend while thermal stability and functional groups on the cellulose surface seemed to differ. All the FT-IR spectra showed 8 main peaks but spectra of bagasse have an additional peak. Stretching vibrations of the O-Hand the C-H stretching group in cellulose molecules were clear for all biomasses. The treatment clearly removed most of aromatic compounds normally attributed to lignin and hemicellulose.

WOOD RESEARCH Volume 66, Number 1, 2021
Samson Masulubanye Mohomane, Setumo Victor Motloung, Lehlohonolo Fortune Koao, and Tshwafo Elias Motaung

Effect of silica on alkaline bagasse cellulose and softwood cellulose

This study investigates the effect of silica on sugarcane bagasse (SCB) and softwood (SW) cellulose. Cellulose was extracted from raw SCB and SW chips using a three-step process, namely thermal pre-treatment, alkaline treatment and bleaching treatment. Alkali treated cellulose was then subjected to silica surface modification using the solvent exchange method. The effect of silica modification on SCB and SW cellulos was investigated using X-ray diffractions analysis (XRD), Fourier transform infrared (FTIR) spectroscopy and optical microscope (OPM) techniques. Both the FTIR and XRD results confirm successful extraction of cellulose from both raw fibers and addition of silane functional groups in the cellulose surface. XRD patterns of all samples revealed typical spectra for natural fibers corresponding to crystalline peaks of cellulose and undissolved amorphous hemicellulose respectively. SCB and SW showed similar increasing patterns of crystallinity with nanosilica surface modification. The surface morphology results showed that both SCB and SW cellulose modified with silica were swollen and displayed small particles agglomerating on the surface of the fibers. The solvent exchange method proved to be a successful method for modifying SCB and SW cellulose with nanosilica. It also proved to be cost-efficient and time-efficient.