Anomalous Dispersion and Dielectric Loss in Polar Polymers

A theory of dielectric loss of polar polymers at high dilution in a nonpolar plasticizer is developed. The theory leads to a broad distribution in relaxation times, associated with the internal rotatory Brownian motion of the hydrocarbon chain. An approximate relation between the degree of polymerization, the frequency of maximum loss, and the viscosity coefficient of a polar plastic is obtained. The loss factor is calculated from the theoretical relaxation time distribution for a mono-disperse polymer and for a poly-disperse polymer with an exponential distribution in chain length. The theoretical loss factor is compared with the experimental loss factor of polyvinyl chloride plasticized with diphenyl. The agreement with experiment is semi-quantitative.