Enthalpies of Dilution, Volumetric Properties, and Refractive Indices of N,N′-Hexamethylenebisacetamide in Aqueous Xylitol or d-Mannitol Solutions at T = 298.15 K

Abstract

The enthalpies of dilution (ΔdilHm), apparent molar volumes (Vϕ), and refractive indices (nD) of N,N′-hexamethylenebisacetamide (HMBA) in aqueous solutions of xylitol and d-mannitol were respectively determined at 298.15 K with the methods of isothermal microcalorimetry, density, and refractive-index measurements. The enthalpic interaction coefficients (h2, h3, and h4), limiting partial molar volumes (Vϕ0), and transfer partial molar volumes (ΔtrsVϕ0) from water to solutions and molar refractions at the sodium-D line (RD) were deduced from the experimental data in the polyols molality range (0 to 0.9) mol·kg–1. The important parameters were interpreted to understand the interactions among solvated solute molecules in HMBA–xylitol (or mannitol)–water ternary systems. The results indicated that the number of hydroxyls in the both polyols could evidently affect the parameters.