With the aim to study the behaviour of polymer solutions, density and ultrasonic velocity of binary mixtures of pentanol with polyethylene glycol diacrylate and polyethylene glycol dimethacrylate have been investigated at 293.15 K, 303.15 K and 313.15 K, under atmospheric pressure. Thermophysical parameters viz. intermolecular free length, internal pressure and pseudo-Grüneisen parameter have been calculated which infer about the interactions and structural changes on mixing pentanol with these polymers. Enthalpy, entropy and Gibbs free energy of activation for viscous flow at different concentrations of polymer solution have been reported. Excess molar volume, deviation in isentropic compressibility, deviation in ultrasonic velocity, excess acoustic impedance and excess molar enthalpy have been calculated and results have been correlated with Redlich-Kister polynomial equation. Density and ultrasonic velocity data have been fitted by third order polynomial equation.