Abstract
Dielectric relaxation was measured with poly (ethylene-1, 2-diphenoxyethane-p, p″-dicarboxylate) (PEBC) in an attempt to clarify the mechanism of relaxation process of aromatic polymers. PEBC is an alternating aromatic copolyether-ester with the same ester part as that of poly (ethylene terephthalate) (PET). The difference spectra obtained by subtraction of the PET spectra exhibited a β relaxation maximum at a higher frequency than that of PET and also showed a lower activation energy than that of PET. From these observations, the difference spectra might be attributed to the ether part of PEBC, suggesting that the ether and ester parts contribute almost independently to the β relaxation of PEBC. This agrees with our previous observation for aromatic polyesters that the correlation of chain motion of flexible parts contributing to β relaxation is interrupted by the presence of an aromatic ring.
