Flory interaction parameter chi for hydrophilic copolymers with water.

In biomedical applications of hydrophilic polymers knowledge is required of the thermodynamic interactions between the candidate biomaterial and biological fluids. Since information on these interactions is not readily available, a new method is proposed here to estimate the copolymer-water Flory interaction parameter, chi, for biomaterials. The method is based on the pairwise thermodynamic interactions of copolymer segments and solvent molecules. It is validated using data for an important biomedical hydrogel, poly(2-hydroxyethyl methacrylate-co-methacrylic acid), in contact with water.