CORRELATION OF DIELECTRIC AND CALORIMETRIC CHARACTERISTICS FOR AN AMORPHOUS DONOR-ACCEPTOR COPOLYMER

Dielectric and calorimetric studies were performed on a series of copolymers with different ratio of electron acceptor (3,5-dinitrobenzoil) and electron donor (phenothiazinyl) side groups. Both the calorimetric glass transition and a relaxation temperature corresponding to dynamic glass transition presented a positive deviation from the weighted average of the homopolymers, correlated with the density of donor-acceptor interactions. For the frequency dependence of alpha temperature an exponential expression was proposed, T-alpha similar to f(0.093), and alpha temperature which would correspond to static electric field was determined and compared with glass transition. From the analysis of isothermal frequency data, the Vogel temperature at which the segmental movement ceases, equivalent to the Kauzmann temperature, was determined and was found to exhibit a relative maximum for the equimolar composition.