Water in methacrylates—I. Sorption and desorption properties of poly(2-hydroxyethyl methacrylate-co-glycol dimethacrylate) networks

Abstract

Sorption and desorption kinetics of water in copolymers of 2-hydroxyethyl methacrylate with ethylene glycol dimethacrylate and oligo (ethylene glycol) dimethacrylates are reported and analysed in terms of Fick's and Frisch's laws. Sorption kinetics range from Fickian to Alfrey Case II with the Frisch parameter n ranging from 0.5–0.9 In desorption, n was less than 0.5 in non-Fickian cases. Diffusivities calculated according to Fick's law are reported. The results are consistent with the dual mode sorption mechanism, i.e. penetration into voids or low density domains followed by redistribution as the high density domains soften and relax.