Protonation of alkanolamines and cyclic amines in water at temperatures from 293.15 to 373.15 K

Abstract

Abstract The protonation properties of amines are of particular interest for the development of thermodynamic models representative of CO2 dissolution in aqueous solutions. This paper reports experimental equilibrium constants of protonation of alkanolamines (2-aminoethanol, 2,2′-iminodiethanol, 2-[bis(2-hydroxyethyl)amino]ethanol, 2-amino-2-methylpropan-1-ol, 2,2′-(methylimino)diethanol and cyclic amines (morpholine, 4-methylmorpholine, pyridine, 1-methyl-piperidine, 2-methyl-piperidine, 2,6-dimethylpiperidine). The equilibrium constants of protonation were determined by potentiometric technique up to 353.15 K and extrapolated up to 373.15 K using experimental enthalpies of protonation.