Sorption of water in nylon 6‐clay hybrid

TLDR

Nylon‑6 clay hybrids, including NCHs and NCHPs with montmorillonite or saponite layers, have been synthesized. Water sorption was measured to determine diffusion and partition coefficients, and a mixing‑law model relating the diffusion coefficient to the constrained‑region fraction was derived with Dₐ = 12.6 × 10⁻⁷ cm²/s and n = 0.585. The hybrids exhibited lower diffusion coefficients than nylon 6, giving superior water‑permeation resistance that decreased further with increasing clay content and could be explained by the constrained‑region contribution. © 1993 John Wiley & Sons, Inc.

Abstract

Abstract Various nylon 6‐clay hybrids, such as molecular composites of nylon 6 and silicate layers of montmorillonite and saponite, NCHs and NCHPs, respectively, have been synthesized. Sorption of water in those hybrids was measured to estimate the resistance to water permeation. The diffusion coefficient D and the partition coefficient K were obtained from the sorption curves. The resistance to water permeation of NCH was superior to that of nylon 6 because of a decrease in D . In NCHP, saponite had a smaller effect on the increase of the resistance. The diffusion coefficients in NCH and NCHP decreased with an increase in the amount of clay minerals. It was found that those diffusion coefficients were well described by the contribution of the constrained region calculated from the storage and the loss modulus at the glass transition temperature. According to the mixing law, the following equation was obtained between the diffusion coefficient D and the fraction of the constrained region C, D = D a (1 – C) 1/ n , where the values of D a (diffusion coefficient in amorphous nylon 6) and n (morphology parameter) were 12.6 X 10 −7 cm 2 /s and 0.585, respectively. © 1993 John Wiley & Sons, Inc.