DIELECTRIC STUDY OF 3 ETHYLENE-CARBON MONOXIDE CO-POLYMERS

In the reported experiments, dielectric absorption measurements are made on three ethylene-carbon monoxide copolymers containing 2. 3, 8. 7, and 18 C equals O per 1000 CH//2 at frequencies ranging from 1 kHz to 1 MHz throughout the 90-373 degree K temperature range. Mean values of the activation energies of the gamma , beta , and alpha relaxations are found to be, respectively, 11. 5, 41. 5, and 31 kcal/mole from measurements done at fixed frequency by varying the temperature and 27 kcal/mole for the alpha relaxation as obtained from measurements at steady temperatures with drifting frequencies. The interaction energy of the CH//2 unit in the crystalline polyethylene chain with its neighbors is calculated on the basis of the chain rotation model as well as of the rotation-translation model proposed by Hoffman et al. It seems that their alpha //c models accounting for the molecular origin of the alpha relaxation have to be rejected.