FREQUENCY-TEMPERATURE RELATIONSHIPS FOR RELAXATIONS IN POLYMERS

Two classes of relaxations have been found in which the relationship between the frequency and the temperature can be defined in terms of a single adjustable parameter. In the first class, the activation entropy is close to zero and [GRAPHICS] where Delta H-not equal is the activation enthalpy. The second class of internal motions occurs close to absolute zero. These relaxations have frequencies proportional to the absolute temperature and are attributed to quantum mechanical tunneling. Relaxations such as gas transitions which have very large apparent activation energies are believed to reflect a distribution of internal motions which is sampled differently at different temperatures.