Abstract

Dielectric and viscoelastic relaxation measurements have been carried out on poly(2-chloroethyl diitaconate) (PDCEI) and poly(3-chloropropyl diitaconate) (PDCPI) between 123 K and temperatures about 293 K above the glass transition temperatures. The two polymers exhibit three peaks, a ?-relaxation in the range from 133 to 193 K (at 1 Hz), a broad ?-process, in the range from 193 to 293 K and a third peak observed in mechanical measurements at 323 K (PDCEI) and 293 K (PDCPI) probably corresponding to the ? dynamic glass transition phenomena. In dielectric measurements, conductive contributions overlap the ?-relaxation precluding the observation of peaks at temperatures above room temperature. The apparent activation energies for the ?-relaxation according to the mechanical and dielectric measurements are close to the values derived from the empirical force field molecular mechanics calculations. A comparison is made between the relaxational data of PDCEI and PDCPI by one hand and poly(di-n-propyl itaconate) (PDPI) and poly(di-n-butyl itaconate) (PDBI) by other. This comparison allows us to conclude the relevant role played by the chlorine atoms not only in the ? relaxations but also in the ? relaxations of PDCEI and PDCPI. © 2004 Elsevier Ltd. All rights reserved.