Dielectric Loss in Poly-(Hexamethylene Adipamide) and Poly-(Hexamethylene Sebacamide) at Low Temperatures

Abstract

The dielectric behavior of samples of nylon 6–6 and nylon 6–10 has been studied in the temperature region from −160° to 60°C at frequencies of 0.1 to 100 kc/sec. The effects of thermal history, electron irradiation, and post irradiation annealing on the two dielectric loss peaks found in this frequency‐temperature range have been explored. Electron irradiation of nylon 6–6 and 6–10 and thermal quenching of nylon 6–6 lowers the γ peak (−70°C at 1 kc/sec for 66 nylon) and raises the β peak (+15°C for 66 nylon at 1 kc/sec). Post irradiation annealing of nylon 6–6 or 6–10 irradiated to low doses (25 to 100 mrad) removes the effect of the irradiation on the dielectric behavior, but on irradiation to high dosages (900–1000 mrad) the dielectric loss values in the region of the β maximum at 0.1 and 1.0 kc/sec are greatly reduced. The frequency shifts of the dielectric loss maxima for all samples give activation energies in kcal/mole which fall in the 8–15 range for the β maximum and 9–19 for the γ maximum. These absorption peaks and the effect of various variables on them are discussed in terms of the molecular structure and possible molecular motions responsible for their occurrence.