## 4 Conclusions  
Densities of MDEA + H\({}_{2}\)O, DMEA + H\({}_{2}\)O, and DEEA + H\({}_{2}\)O mixtures were measured for amine mass fraction range from 0.3 to 1 and for the temperature range from 293.15 K to 353.15 K. The measured density of MDEA + H\({}_{2}\)O mixtures increases with increase of MDEA concentration until a maximum and then decreases. For the density of DMEA + H\({}_{2}\)O and DEEA + H\({}_{2}\)O mixtures, a density maximum reported at \(x_{1}\) = 0 and density continues to decrease with increase of amine concentration. The excess molar volumes \(V^{E}\) were negative for the all mixtures and temperature dependent. This indicates efficient molecular packing and existence of strong intermolecular interactions such as H-bonds among unlike molecules in the mixtures. The density correlations based on Redlich-Kister type polynomials for excess molar volume \(V^{E}\) and density deviation \(ln(\rho_{\gamma})\) represented measured densities with good accuracy signifying their applicability to perform engineering calculations. The proposed Redlich-Kister type polynomials with linear temperature dependency were able to calculate partial molar volume \(\overline{V_{1}^{\infty}}\) of amines at infinite dilution in H\({}_{2}\)O with acceptable accuracies compared to values reported in literature.  
Viscosities of MDEA + H\({}_{2}\)O, DMEA + H\({}_{2}\)O, and DEEA + H\({}_{2}\)O mixtures were measured for amine mass fraction \(w_{1}\) range from 0.3 to 1 for the temperature range from 293.15 K to 363.15 K. The calculated viscosity deviation \(\eta^{E}\) and excess free energy of activation for viscous flow \(\Delta\)G\({}^{E*}\) could be explained the intermolecular interactions among unlike molecules in the mixtures. The proposed viscosity correlations were able to represent measured data with acceptable accuracies. The [PERSON]'s three-body model was adopted to correlate kinematic viscosities calculated from measured viscosities and densities at different concentrations and temperatures. The accuracies of the data fits into [PERSON]'s three-body model are relatively low compared to the proposed viscosity correlations in this work and it is recommended to examine [PERSON]'s four-body model for better data representation.  
The following are available online at [[http://www.mdpi.com/2076-3417/10/9/3196/s1](http://www.mdpi.com/2076-3417/10/9/3196/s1)]([http://www.mdpi.com/2076-3417/10/9/3196/s1](http://www.mdpi.com/2076-3417/10/9/3196/s1)), Figure S1: Comparison of measured density of MDEA (1) + H\({}_{2}\)O (2) mixtures with literature, Figure S2: Comparison of measured density of DMEA (1) + H\({}_{2}\)O (2) mixtures with literature, Figure S3: Comparison of measured density of DEEA (1) + H\({}_{2}\)O (2) mixtures with literature, Figure S4: Comparison of measured viscosity of MDEA (1) + H\({}_{2}\)O (2) mixtures with literature, Figure S5: Comparison of measured viscosity of MDEA (1) + H\({}_{2}\)O (2) mixtures with literature, Figure S6: Comparison of measured viscosity of DEEA (1) + H\({}_{2}\)O (2) mixtures with literature, Table S1: Comparison of measured density of DMEA (1) + H\({}_{2}\)O (2) mixtures with literature, Table S3: Comparison of measured viscosity of DMEA (1) + H\({}_{2}\)O (2) mixtures with literature.  
Supervision, L.E.O. and D.A.E.; Writing--original draft, S.S.K. All authors have read and agreed to the published version of the manuscript.  
This work was funded by the Ministry of Education and Research of the Norwegian Government.  
The authors declare no conflict of interest.