Complex thermal effusivity of glassy polyhydric alcohols

The temperature dependence of the complex thermal effusivity has been measured above a glass transition point by the photoacoustic method in the 1,2-propanediol and 1,2-ethanediol system. The concentration dependence of the parameter of the Vogel-Tammann-Fulcher law has been determined. The distribution of a relaxation time has been estimated by the Cole-Cole plot. These thermal properties have been compared with the dielectric properties. The mean thermal relaxation frequency is found to be in agreement with the dielectric one. Whereas it is found that the parameter of the Davidson-Cole formula for thermal relaxation is different from that of dielectric one.