Comparative study of poly-dialkyl itaconates by TSDC and TW

The dielectric activity of poly-dimethyl itaconate (PDMI), poly-diethyl itaconate (PDEI) and poly dipropyl itaconate (PDPI) has been carried out by thermo stimulated discharge current (TSDC) techniques. Two relaxational zones are found. The TSDC global spectra corresponding to PDMl, PDEI and PDPI exhibit a moderate subglass relaxation, related to motion of ester side groups. Moreover, prominent peaks associated with the glass-rubber transition located at 368K, 320K and 308K, respectively, are observed. More detailed information about the fine structure of the subglass processes has been obtained by partial depolarization of poling samples (Thermal windows, TW). By fitting the experimental data to standard models, the kinetic parameters of the relaxations observed for each polymer, have been evaluated. Finally, a comparative study of the poly-dialkyl itaconates, are discussed in terms of molecular mobility.