The dielectric properties of dry and water‐saturated nylon‐12

The dielectric relaxation of 30% crystalline Nylon‐12 of molecular weight 20,000 has been studied at frequencies from 12 Hz to 0.1 MHz and temperatures from 77 to 375 K, and the effect of water on the relaxation spectra has been investigated. Absorbed water increases both the rate and the intensity of both its α‐and β‐relaxation processes and increases the rate but decreases the intensity of its γ‐relaxation process. These results are interpreted in terms of the hydrogen bonding effects of water on localized motions of dipoles in Nylon‐12. The relatively large half‐width of the α‐relaxation, which becomes better resolved at high temperatures, is attributed mainly to the random distribution of crystalline regions in the polymer. It is suggested that water lowers the steric hindrance for the localized mode of dipolar reorientation and causes a redistribution of local sites such that the β‐relaxation process grows at the expense of the γ‐process.