Effect of temperature on ultrasonic velocity and thermodynamic parameters of cardo aromatic polysulfonate solutions

摘要

Density (ρ), viscosity (η) and ultrasonic (U) velocity (2 MHz) of pure solvents (1,2-dichloro ethane, chloroform, THF and 1,4-dioxane) and solutions of polysulfonate (PANDPE) in these solvents have been investigated at 303, 308 and 313 K. Acoustical parameters [specific acoustical impedance (Z), isentropic compressibility (κ)_s, Rao's molar sound function(R), Van der Waals constant (b), internal pressure (π), free volume (V_f), intermolecular free path length (L_f), classical absorption coefficient (α/f~2)_(cl) and viscous relaxation time (τ)] have been determined from ρ, η and data and correlated with concentration at 303,308 and 313 K. A fairly good to excellent correlation between a given parameter and concentration is observed at all temperatures and solvent systems studied. Linear or nonlinear increase or decrease of acoustical parameters with concentration and temperature indicated existence of strong molecular interactions. Positive values of solvation number suggested structure-forming tendency of the polymer.