Experimental and Simulation Studies of the Dielectric Relaxation of 2,2-Bis[4-(2-hydroxyethoxy)phenyl]propane Diacetate (DDA) in the Liquid State

Abstract

Molecular dynamic simulations of the time dipole correlation function g(t) were performed, at several temperatures, for both an isolated molecule of 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane diacetate (DDA) and a canonical ensemble of these molecules contained within a cubic box with periodic boundary conditions. To perform the simulations in a reasonable computing time, the calculations were carried out at temperatures well above the glass-transition temperature. Fitting of the relaxation response in the time domain to the KWW equation g(t) = exp[−(t/τ*)β] is good for rather low values of the stretch exponent. The nature of the simulated relaxations is discussed.