Dielectric Properties of Poly(2, 6-Dimethyl Phenylene Oxide)

The dielectric relaxation of amorphous bulk poly(2, 6-dimethyl phenylene oxide) (PPO) has been measured between −160° and 260°C over a frequency range extending from 0.1 to 10 kHz. Two broad loss peaks of comparable intensities are observed-a high-temperature α relaxation identified with the glass transition and a low-temperature γ relaxation of uncertain origin. The intensity of the α relaxation can be well accounted for in terms of a loss of orientational dipolar correlation in a calculation based on a consideration of a rotational isomeric model and of the geometry of the PPO chain.