Starch plasticization with choline dihydrogencitrate-based deep eutectic system

Two-component deep eutectic solvents (DES) based on choline dihydrogencitrate and glycerol or urea were tested as starch plasticizers. Thermal analysis techniques were applied to characterize the properties of starch/DES systems. The X-ray diffractometry measurements revealed a significant decrease in crystallinity indicating that used DES exhibited the ability to penetrate the ordered regions of potato starch, which is a necessary feature of a true plasticizer. However, the differential scanning calorimetry and dynamic thermal analysis results surprisingly showed an increase of T_g of starch materials indicating chemical crosslinking at elevated temperature. The eutectic solvents based on choline dihydrogencitrate could act as a plasticizer and a simultaneously crosslinking agent.