Ingress of water into solid nylon 6.6

Abstract

The ingress of water into Nylon 6.6 has been studied over a range of temperatures by nuclear magnetic resonance imaging techniques. The results have been used to extract the translational diffusion coefficient as a function of water concentration for various temperatures. These results in turn allow the activation energies to be evaluated. Other experiments have been made to measure the spin relaxation times T₁ and T₂. The results are interpreted using a two-phase exchange model from which good agreement for both the diffusion and relaxation-time data is obtained. High-pressure diffusion results also presented support the view that water is taken up preferentially at the amorphous amide sites in the Nylon and that pressure increases serve to force water onto sitccupied sites and/or onto occupied sites, giving up to three waters per amide site.