Abstract
The esterification of bagasse with glutaric anhydride could increase surface adhesion compatibility and the surface of derived polymers has the potential of immobilizing peptides or proteins for biomedical application. Due to its complicated components, the esterification mechanism of bagasse esterified with glutaric anhydride in ionic liquids has not been studied. In this paper, the homogenous esterification of bagasse with glutaric anhydride was comparatively investigated with the isolated cellulose, hemicelluloses, and lignin in 1-allyl-3-methylimidazolium chloride (AmimCl) to reveal the reaction mechanism. Fourier transform infrared (FT-IR) indicated that the three components (cellulose, hemicelluloses, and lignin) were all involved in the esterification. The percentage of substitution (PS) of bagasse was gradually improved with the increased dosage of glutaric anhydride (10–40 mmol/g), which was primarily attributed to the increased esterification of cellulose and hemicelluloses. However, the PS fluctuation of lignin led to a decrease in the PS of bagasse at high glutaric anhydride dosage (50 mmol/g). The esterification reactivity of bagasse components followed the order of lignin > hemicelluloses > cellulose. The esterification mechanism was proposed as a nucleophilic substitution reaction. Nuclear magnetic resonance (NMR) analysis indicated that lignin aliphatic hydroxyls were prior to be esterified, and primary hydroxyls were more reactive than secondary hydroxyls in cellulose and hemicelluloses.
Highlights
The challenges caused by the depletion of fossil fuel sources and the volatility of oil prices has lead to the increasing pressure on the generation of industry [1]
By comparison with unmodified lignin, the intensity of the absorbance at 1718 cm−1 in the esterified lignin (Figure 1d) increased obviously, indicating the attachment of glutaryl groups onto lignin. These results indicated that cellulose, hemicelluloses, and lignin were all involved in the esterification with glutaric anhydride during the homogenous esterification of bagasse in allyl-3-methylimidazolium chloride (AmimCl)
Hemicelluloses and lignin were all involved in the homogeneous esterification of bagasse with glutaric anhydride in AmimCl
Summary
The challenges caused by the depletion of fossil fuel sources and the volatility of oil prices has lead to the increasing pressure on the generation of industry [1]. To cope with the pressure, it is imperative to manufacture renewable materials, transportation fuels and chemicals to supplement or replace those derived from petroleum [2]. As the sustainable alternative with low cost and great renewability, biomass resources draw significant attention to the potential manufacturing biofuels and chemicals, especially lignocellulose biomass. Distributing in many kinds of plants, lignocellulose is mainly composed of carbohydrate polymers (cellulose and hemicelluloses) and polyphenol-based lignin [3]. It is insoluble in conventional solvents due to the complicated structures and the complex linkages among different components, limiting its application and making it underutilized. Challenges associated with the insolubility can be resolved by the derivatization of lignocellulose. Esterification is one of the most common derivatization reactions of lignocellulose
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
