Work

Acylation of starch in the presence of carboxylic acids and amides as organocatalysts and as hydrogen bond donors in deep eutectic solvents

Year: 2025

Type: article

Abstract: This study aims to investigate starch acylation using a new type of green solvents, namely deep eutectic solvents (DES), consisting of choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and a series of carboxylic acids (citric, tartaric, malic, lactic, oxalic) or amides (urea, thiourea) as organocatalysts and hydrogen bond donors; and to compare acids versus amides as organocatalysts. The substitution degree (DS), determined by 1 H NMR and confirmed by FTIR and 13 C NMR, increased from 1.49 (reaction yield of 63.2 %) to 2.22 (reaction yield of 69.4 %) with increasing acetic anhydride quantity, and from 0.13 (69.3 %) to 2.03 (59.5 %) with temperature increasing from 90 °C to 110 °C. Spectroscopic analysis revealed the presence of carbamate byproducts, in the samples acylated in the presence of DESs with urea/thiourea. X-ray diffraction (XRD) patterns showed that the structure of acylated samples differs in acid catalysis compared to basic catalysis, from amorphous to crystalline, respectively, and the crystallinity degree decreased with DS.

Source: International Journal of Biological Macromolecules

DOI: 10.1016/j.ijbiomac.2025.148696

Authors: Gheorghiţa Mitran, Octavian Dumitru Pavel, Anamaria Hanganu

Institution: University of Bucharest

Language: English

Topic: Ionic liquids properties and applications

Subfield: Catalysis

Field: Chemical Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,390

Funder: Universitatea din București