Water sorption by poly(tetrahydrofurfuryl methacrylate-co-2-hydroxyethyl methacrylate). I. A mass-uptake study

Cylindrical samples (approximate to 5 mm x 20 mm) of poly(2-hydroxyethyl me thacrylate) and copolymers of 2-hydroxyethyl methacrylate and furfuryl meth acrylate were prepared, and the sorption of water into these cylinders was studied by the mass-uptake method and by the measurement of the volume chan ge at equilibrium. The equilibrium water content and volume change for the cylinders both varied systematically with the copolymer composition. The di ffusion of water into the cylinders followed Fickian behavior, with the dif fusion coefficients, dependent on the copolymer composition, varying from 2 .00 x 10(-11) m(2)s(-1) for poly(2-hydroxyethyl methacrylate) to 5.00 x 10( -12) m(2)s(-1) for poly(2-hydroxyethyl methacrylate-co-tetrahydrofurfuryl m ethacrylate) with a 1:4 composition. The polymers that were rich in 2-hydro xyethyl methacrylatc were characterized by a water-sorption overshoot, whic h was attributed to a slow reorientation of the polymer chains in the swoll en rubbery regions formed after wafer sorption. (C) 2000 John Wiley & Sons, Inc.