The densities of pure components and the binary mixtures of (1

3-propanediol+water)

(1

3-propanediol+ethanol) were measured at 328.15—348.15 K for the liquid region and under ambient pressure over the whole range of compositions.The excess molar volumes were calculated by using the measured experimental densities.The excess molar volumes were negative over the whole mole fraction range for the temperature range studied for the binary mixtures.Volumetric data indicated that the intermolecular interaction between different molecules was stronger than that between the same molecules and packing effect was resulted from different molecule sizes in the studied mixtures.