Volumetric properties of binary mixtures of some <i>n</i>-alkoxyethanols with 2-pyrrolidinone and N-methyl-2-pyrrolidinone at 298.15 K

2017-2024The excess molar volumes (VE) for binary liquid mixtures of n-alkoxyethanol + 2-pyrrolidi none or N-methyl-2-pyrrolidinone have been measured with a continuous dilution dilatometer at 298.15 K and atmospheric pressure as a function of composition. The alkoxyethanols are 2-methoxyethanol (CH3OCH2CH2OH), 2-ethoxyethanol (C2H5OCH2CH2OH), and 2-butoxyethanol (C4H9OCH2CH2OH). In all mixtures the excess molar volumes are negative across the entire composition range. In each case the excess molar volumes decrease as the alkyl chain length of the alkoxyethanol increases while it increases, from 2-pyrrolidinone to N-methyl-2-pyrrolidinone. The results have been used to estimate the excess partial molar volumes iE of the components. The change of VE and iE with composition and the number of alkyl chain-length in the alkoxyethanol molecule is discussed with a view to understand some of the molecular interactions present in alkoxyethanol-cyclic amide mixtures