Surface Tension of Binary Mixtures of Water +N-Methyldiethanolamine and Ternary Mixtures of This Amine and Water with Monoethanolamine, Diethanolamine, and 2-Amino-2-methyl-1-propanol from 25 to 50 °C

The surface tension of aqueous solutions of N -methyldiethanolamine and diethanolamine + N -methyldiethanolamine, monoethanolamine + N -methyldiethanolamine and 2-amino-2-methyl-1-propanol + N -methyldiethanolamine was measured at temperatures from 25 °C to 50 °C. For binary mixtures the concentration range was 0−50 mass % N -methyldiethanolamine, and for the tertiary mixtures the concentration range for each amine was 0−50 mass %. The experimental values were correlated with temperature and mole fraction. The maximum deviation in both cases was always less than 0.5%.