Poly(imide–amide)–poly(ethylene adipate) hybrid networks. II. Dielectric studies

Dielectric techniques, including thermally stimulated depolarization currents and isothermal discharging currents measurements in addition to classical dielectric relaxation spectroscopy, were employed to investigate molecular mobility in the poly(imide–amide)–poly(ethylene adipate) (PIA–PEA) hybrid materials with short (Mn=1.300 g mol−1) PEA crosslinks. The techniques used covered together the frequency range from 10−4 to 106 Hz. Secondary relaxations, the primary α relaxation of the PEA component, interfacial polarization and dc conductivity were studied. Significant reduction of the magnitude and broadening of the response is observed for the α relaxation of the PEA component in the hybrids. The results obtained have been analyzed in terms of morphological characterization. They suggest appearance of long-range connectivity of the PEA component in the hybrids at PEA contents between 60 and 70 wt%.