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

The enthalpies of dilution (Delta H-dil(m)), apparent molar volumes (V-phi), and refractive indices (n(D)) 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 (h(2), h(3), and h(4)), limiting partial molar volumes (V-phi(0)), and transfer partial molar volumes (Delta(trs), V-phi(0)) from water to solutions and molar refractions at the sodium-D line (R-D) 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.