Preparation of a new BTEAB/DMSO deep eutectic solvent for highly efficient starch dissolution and succinylation

Area of Science:

• Green Chemistry
• Materials Science
• Biomass Processing

Background:

• Deep eutectic solvents (DES) offer tunable properties for chemical applications.
• Starch processing often requires harsh conditions or inefficient solvents.
• Sustainable methods for polysaccharide modification are in high demand.

Purpose of the Study:

• To prepare and characterize a novel DES based on benzyltriethylammonium bromide/dimethyl sulfoxide (BTEAB/DMSO).
• To evaluate the BTEAB/DMSO DES as a medium for starch dissolution and esterification.
• To explore the potential of this DES for sustainable starch valorization.

Main Methods:

• Preparation and physicochemical analysis of BTEAB/DMSO DES.
• Starch dissolution experiments at elevated temperatures.
• Catalyst-free esterification of starch using succinic anhydride within the DES.
• Comprehensive characterization of modified starch using FTIR-ATR, H1 NMR, XRD, SEM, EDX, and TGA.

Main Results:

• The BTEAB/DMSO DES exhibits a low eutectic point (0 °C) and strong intermolecular interactions.
• High starch dissolution capacity (up to 22 wt%) was achieved at 90-95 °C.
• Successful catalyst-free esterification of starch was demonstrated, yielding succinylated starch.
• Characterization confirmed significant structural and morphological changes in the modified starch, including loss of crystallinity and native granules.

Conclusions:

• The BTEAB/DMSO DES is a highly effective and stable solvent for biomass processing.
• This DES serves as an efficient reaction medium for sustainable starch modification.
• The study presents a promising eco-friendly strategy for polysaccharide valorization using DES.