Density, dynamic viscosity, excess properties and intermolecular interaction of triethylene glycol + N,N‑dimethylformamide binary mixture

Abstract

The density (ρ) and dynamic viscosity (v) data of the N,N‑dimethylformamide (DMF) + triethylene glycol (TEG) binary mixtures were measured in the entire mole fraction at five equidistant temperatures from (293.15 to 318.15) K under atmospheric pressure. On the basis of ρ and v data, he apparent molar volume (Vφ,1 and Vφ,2), partial molar volume (V1¯ and V2¯), excess molar volume (VmE), viscosity deviation (Δη), and excess volume expansivity rate (αE) values were calculated. In the whole molar fraction range, all the VmE values were negative and presented the minimum values at x1 ≈ 0.43. To explore intermolecular interaction between DMF and TEG, pure DMF, pure TEG and their mixtures were characterized by FTIR, UV–Vis, and 1H NMR technologies. The consequences suggested that hydrogen bond between hydroxyl H atoms of TEG and O atoms of DMF was formed as follows: (CH3)2NCHO⋯HOCH2CH2OCH2CH2OCH2CH2OH⋯OCHN(CH3)2.