HIGH-TEMPERATURE DIELECTRIC-RELAXATION IN NYLON-12 AND THE EFFECTS OFANNEALING AND ABSORBED WATER

To understand the molecular origin for the high-temperature, lowest-fr equency relaxation process in nylon 12, the dielectric behaviour of it s water-saturated (16 mol% water) state has been studied at 423 K and over the frequency range from 12 to 10(5) Hz. In addition, the effects of annealing at 423 K have been investigated by calorimetric and diel ectric methods. The dipolar relaxation spectra, which have been resolv ed by the procedure described in the preceding paper (J. Chem. Sec., F araday Trans., 1995, 91, 329), have an asymmetric distribution of rela xation times. The static permittivity remains constant on annealing fo r dry nylon 12, but decreases for a water-saturated sample whose relax ation time also decreases. It is concluded that the relaxation involve s motion of protons over intermolecular barriers in the H-bond linkage s. The decrease in the amount of amorphous phase and the change in the crystal forms on annealing have a greater effect on the dielectric be haviour when nylon 12 contains water.