Ultrasonic Study of Molecular Interactions in Polymeric Solution of Polypropylene Glycol-400 and Ethanol at 303 K

Abstract

A comprehensive ultrasonic investigation of molecular interactions in the polymeric solution of polypropylene glycol (PPG)-400 and ethanol at 303 K has been performed using the data available in literature. Several acoustic parameters such as acoustic impedance, isothermal compressibility, molar sound velocity, molar adiabatic compressibility, internal pressure, free volume, van der Waals constants, molar cohesive energy and relaxation time have been explored. Thermo-dynamical parameters viz.: available volume, intermolecular free length, relative association, surface tension, pseudo-Gruneisen parameter, Debye temperature, diff usion constant, coefficient of thermal conductivity and latent heat of melting have been evaluated. Several thermo- elastic parameters such as Young modulus, shear modulus, bulk modulus and Poisson's ratio are also determined. Excess parameters are computed to study the relative molecular interactions and strength of interaction between the constituents of the polymer mixture. The volume expansivity data is used to evaluate Moelwyn-Hughes parameter, reduced volume, reduced isothermal bulk modulus, Sharma's constants, Huggins parameter, isobaric, isochoric, and isothermal lattice Gruneisen parameters, fractional free volume, repulsive exponent, Bayer's non-linear parameter, cohesive energy density and characteristic temperature. Schaaff 's collision factor theory, Jacobson's free length theory, Nomoto's relation, Van Dael-Vangeel relation, impedance dependence relation, Junjie relation and ideal mixing relation have been used to evaluate ultrasonic velocities in the system under study. The obtained results have been compared with earlier experimental results. The non-ideal behaviour of the mixture has been explained in terms of its composition and variation of its acoustical and thermo-dynamical parameters.