Organosolv lignin aggregation behaviour of soluble lignin extract from Miscanthus x giganteus at different ethanol concentrations and its influence on the lignin esterification

Chemical and Biological Technologies in Agriculture

Muhammad Hazwan Hamzah¹  Steve Bowra²  Philip Cox³ 

[1] Department of Biological and Agricultural Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia;SMART Farming Technology Research Centre, Faculty of Engineering, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia;School of Chemical Engineering, University of Birmingham, B15 2TT, Edgbaston, UK;Phytatec (UK) Ltd., SY23 3EB, Plas Gogerddan, Aberystwyth, UK;School of Engineering, University of Greenwich, Medway Campus, Central Avenue, ME4 4TB, Chatham Maritime, Kent, UK;

关键词: Lignocellulosic;    Lignin;    Aggregates;    Concentration;    Esterification;   

DOI  :  10.1186/s40538-021-00263-2

来源: Springer

【 摘 要 】

BackgroundLignin is the second most abundant naturally occurring biopolymer from lignocellulosic biomass. While there are several lignin applications, attempts to add value to lignin are hampered by its inherent complex and heterogenous chemical structure. This work assesses the organosolv lignin aggregates behaviour of soluble lignin extract derived from Miscanthus × giganteus using different ethanol concentrations (50%, 40%, 30%, 20%, 10% and 1%). The effect of two different lignin concentrations using similar ethanol concentration on the efficacy of esterification was studied.ResultsOverall, particle size of lignin analysis showed that the particle size of lignin aggregates decreased with lower ethanol concentrations. 50% ethanol concentration of soluble lignin extract showed the highest particle size of lignin (3001.8 nm), while 331.7 nm of lignin particle size was recorded at 1% ethanol concentration. Such findings of particle size correlated well with the morphology of the lignin macromolecules. The lignin aggregates appeared to be disaggregated from population of large aggregates to sub-population of small aggregates when the ethanol concentration was reduced. Light microscopy images analysis by ImageJ shows that the average diameter and circularity of the corresponding lignin macromolecules differs according to different ethanol concentrations. The dispersion of lignin aggregates at low ethanol concentration resulted in high availability of hydroxyl group in the soluble lignin extract. The efficacy of the lignin modification via esterification was evidenced directly via FTIR using the similar ethanol concentration of soluble lignin extract at different lignin concentrations.ConclusionThis study provided the understanding of detail analysis on particle size determination, microscopic properties and structural insights of lignin aggregates at wider ethanol concentrations. The esterified lignin derived at 5 mg/mL is suggested to expand greater lignin functionality in the preparation of lignin bio-based materials.

【 授权许可】

CC BY