Hydrophilic sponges based on poly(hydroxyethyl acrylate)

Hydrophilic sponges were prepared by co-polymerisation of hydroxyethyl acrylate and ethylene-glycol dimethacrylate in solution. The porous structure of the sponge is due to the segregation of the solvent from the polymer network during the polymerisation process as the result of a large excess of solvent. The influence of the solvent and the monomer/solvent ratio on the formation of the porous structure is studied. The morphology of the samples was examined in a scanning electron microscope equipped with a cryounit using the low-temperature freeze drying technique cryogenic scanning electron microscope (cryoSEM). Equilibrium water sorption isotherms of the sponge and the parameters that fit the Guggengeim-Anderson-De Boer equation are presented. 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.