PH-SENSITIVE HYDROGELS BASED ON HYDROXYETHYL METHACRYLATE AND POLY(VINYL ALCOHOL) METHACRYLATE

Hydrogels, derived from the copolymerization of HEMA and PVA-MA with low concentrations of TMPTMA, were prepared. By increasing the amount of PVA-MA in the hydrogel, the water content increased, but the mechanical strength decreased instead. The PVA-MA containing polymeric hydrogel swelled in responding to the pH changes from 3 to 7. The linear swellability can be increased either by increasing PVA-MA content or by decreasing TMPTMA concentration. While both NaCl and CaCl2 had little effects on the swelling, urea suppressed the pH induced gel expansion significantly.