TY - JOUR
T1 - Degradation of deep-eutectic solvents based on choline chloride and carboxylic acids
AU - Rodriguez Rodriguez, Nerea
AU - van den Bruinhorst, Adriaan
AU - Kollau, Laura J.B.M.
AU - Kroon, Maaike C.
AU - Binnemans, Koen
PY - 2019/5/28
Y1 - 2019/5/28
N2 - Mixtures of carboxylic acids and choline chloride are one of the most commonly used families of deep-eutectic solvents. The thermal and long-term stability of carboxylic acid-choline chloride (ChCl) deep-eutectic solvents was investigated. This family of DESs was found to degrade due to an esterification reaction, mainly between the carboxylic acid and the alcohol moiety of ChCl. The esterification reaction occurs even at room temperature over extended periods of time and is promoted at elevated temperatures. The esterification reaction takes place independently of the preparation method used. Moreover, the deep-eutectic solvent malonic acid-ChCl (xChCl = 0.50) was found to decompose into acetic acid and carbon dioxide when prepared via the heating method, or when heated after preparation at room temperature. Therefore, the applicability of carboxylic acid-ChCl-based solvents is compromised.
AB - Mixtures of carboxylic acids and choline chloride are one of the most commonly used families of deep-eutectic solvents. The thermal and long-term stability of carboxylic acid-choline chloride (ChCl) deep-eutectic solvents was investigated. This family of DESs was found to degrade due to an esterification reaction, mainly between the carboxylic acid and the alcohol moiety of ChCl. The esterification reaction occurs even at room temperature over extended periods of time and is promoted at elevated temperatures. The esterification reaction takes place independently of the preparation method used. Moreover, the deep-eutectic solvent malonic acid-ChCl (xChCl = 0.50) was found to decompose into acetic acid and carbon dioxide when prepared via the heating method, or when heated after preparation at room temperature. Therefore, the applicability of carboxylic acid-ChCl-based solvents is compromised.
KW - Carboxylic acid
KW - Choline chloride
KW - Decomposition
KW - Deep-eutectic solvent
KW - Esterification
KW - Malonic acid
UR - http://www.scopus.com/inward/record.url?scp=85070217848&partnerID=8YFLogxK
U2 - 10.1021/acssuschemeng.9b01378
DO - 10.1021/acssuschemeng.9b01378
M3 - Article
AN - SCOPUS:85070217848
SN - 2168-0485
VL - 7
SP - 11521
EP - 11528
JO - ACS Sustainable Chemistry & Engineering
JF - ACS Sustainable Chemistry & Engineering
IS - 13
ER -
