Dielectric relaxation spectroscopy of poly(ethylene terephthalate)

Contour maps of dielectric loss tangent within the ranges 0.1 Hz to 3 MHz and ?175 °C to +190 °C are presented for a commercial poly(ethylene terephthalate) (PET) in two initial states of crystallinity. Individual absorption regions resemble those for poly(butylene terephthalate) and are attributed to carbonyl‐driven α‐ and β‐relaxation processes and to Maxwell–Wagner–Sillars polarizations. Possible causes are considered for the asymmetry and structure apparent in the α‐peak of partially crystalline PET. © 2001 Society of Chemical Industry