Hydrophilic sponges based on poly(hydroxyethyl acrylate)

Hydrophilic sponges were prepared by co-polymerisation of hydroxyethyl acry late and ethylene-glycol dimethacrylate in solution. The porous structure o f the sponge is due to the segregation of the solvent from the polymer netw ork during the polymerisation process as the result of a large excess of so lvent. The influence of the solvent and the monomer/solvent ratio on the fo rmation of the porous structure is studied. The morphology of the samples w as examined in a scanning electron microscope equipped with a cryounit usin g the low-temperature freeze drying technique cryogenic scanning electron m icroscope (cryoSEM). Equilibrium water sorption isotherms of the sponge and the parameters that fit the Guggengeim-Anderson-De Boer equation are prese nted. The water uptake in immersion in liquid water can be used to estimate the volume fraction of pores in the sponge. (C) 2001 Elsevier Science B.V. All rights reserved.