Crosslinked poly(vinyl alcohol) hydrogels as swollen elastic networks

Abstract Transparent crosslinked PVA hydrogels were prepared by electron beam irradiation of aqueous solutions under nitrogen. These weak hydrogels, upon swelling at 30°C in water, showed low elastic moduli (up to 50 psi), low ultimate tensile strength (up to 4 psi), and low extensibility to break (not higher than 85%). Values of the molecular weight between crosslinks M c were calculated from swelling and from tensile experiments. In fact, two values of M c were calculated for each swelling experiment, (a) allowing for observed variation in the polymer–solvent interaction parameter χ 1 with concentration, and (b) fixing χ 1 = 0.494 according to literature data. The correlation of the M c obtained from tensile data with the M c obtained from swelling data, by (a) or (b), was approximately linear and gave the same per cent agreement.