POLY(2-HYDROXYETHYL METHACRYLATE) (PHEMA) POLY(STYRENE-CO-ACRYLAMIDE)(PSAM) BLENDS - MISCIBILITY AND HYDROGEL PROPERTIES/

The blend miscibility of poly(2-hydroxyethyl methacryl ate)(PHEMA) and poly(styrene-co-acrylamide)(PSAm) was studied by DSC. A 'miscible win dow' was found in the range 47-57 mol% of acrylamide in blending PSAm with PHEMA (1:1 w/w) and was analysed by the mean-field theory. The wa ter content and permeability coefficients of proteins were measured. T he results show that the water content of the blends depends on the co mposition of PSAm and the blends, and the behaviour of blends swollen in water is Fickian type. However, the permeability of the solutes not only related to water content, but was also affected by phase behavio ur. Controlled release of somatotropin from a cylindrical device coate d with PHEMA/PSAm was achieved.