Dielectric relaxation in poly(1,4-phenylene terephthalamide)

The dielectric behavior of poly(1,4‐phenylene terephthalamide) is reported in this paper as a function of frequency (400 Hz–100 kHz), temperature (30–290°C), and the degree of polymerization (134–228). The general behavior of all the samples of different degrees of polymerization is the same except for the occurrence of the peaks at different positions on the frequency and temperature scales. This difference in behavior could be because of the combined effect of the difference in molecular weights and packing of molecules. The data are completely analyzed for the sample with degree of polymerization n = 210. Two distinct processes are observed, one being observed in the entire temperature range, another orginating in the vicinity of glass transition temperature. The former is analyzed in terms of Cole–Cole distribution and the latter is conformed with a nonexponential decay function. Activation energies are calculated from plots of I/T vs. In τ.