| Abstract: | Densities, excess volumes and heats of mixing, heat capacities, refractive indices and viscosities of various N-methyl-2-pyrrolidinone (NMP)-water mixtures are reported. The excess volumes and heat of mixing are negative and show their greatest deviations from ideality at 0.3 - 04 mole fraction NMP. The viscosity of the system passes through a maximum in the same region of solvent composition. These data indicate strong interaction between NMP and water and suggest the existence of transient polymeric species of the type — (NMP · 2H2O)n?. |
