Dielectric properties of polystyrene and some polychlorostyrenes from 4°K to room temperature

Dielectric measurements of carefully purified specimens of polystyrene and poly(2,3,4 or 3,4‐chlorostyrene) have been obtained at audio frequencies ranging from 0.1 to 20 kHz and at temperatures between 4 and 300°K. Each of the samples exhibits a dielectric loss maximum in the range 15–50°K. The temperature of the maximum loss decreases with the addition of a substituent which lowers the symmetry of the pendant phenyl group. The results are explained by a model which invokes a coupling mechanism between two distinct modes of side group motions. This same model also explains some results of previously reported measurements of mechanical losses in similar polymers.