N, N-dimethylacetamide+2-alkanone systems at several temperatures. Application of Flory's model to tertiary amide+ n-alkanone systems]]>

摘要

AbstractData on density,ρ, speed of sound,c, and refractive index,nD, have been reported at (293–303.15) K for theN,N-dimethylacetamide (DMA)+CH3CO(CH2)u?1CH3(u=1, 2, 3) systems, and at 298.15K for the mixture withu=5. These data have been used to compute excess molar volumes,VmE, excess adiabatic compressibilities,κSE, and excess speeds of soundcE. NegativeVmEvalues indicate the existence of structural effects and interactions between unlike molecules. From molar excess enthalpies,HmE, available in the literature forN,N-dimethylformamide (DMF), orN-methylpyrrolidone (NMP)+n-alkanone systems, it is shown: (i) amide-ketone interactions are stronger in DMF systems than in those with NMP; (ii) they become weaker whenuincreases in mixtures with a given amide. Structural effects largely contribute toHm展开▼