Hydrogel Characterization in Aqueous Environments

Poly(2-hydroxyethyl methacrylate), pHEMA, has been used for thickening, stabilizing, flocculating, clarifying, complexing, and moisture retaining agents. In earlier reports the purification problems of HEMA were addressed as well as the effects of low levels of methacrylic acid, MAA, incorporated into a lightly cross-linked gel. The degree of swelling of pHEMA gels in water is critically dependent upon the amount of MAA and cross-linking agent, and obviously upon the pH of the media. This report further characterizes the behavior of the polymer and its formulation