Preparationand Characterization of pH-Sensitive Hydrogels Based on Crosslinked Maleic Anhydride-Styrene-Methyl Methacrylate Terpolymer

In this study, the hydrogels have been synthesized by the crosslinking reactions maleic anhydride-styrene-methyl methacrylate terpolymer with N, N'-methylene-bis-acrylamide and glutaraldehyde in various crosslinker ratios. Crosslinking reactions were carried out in the presence of tetrahydrofuran as solvent at 25-50ºC for different time period, and the resulting material properties compared. The best conditions for effective crosslinking, i.e., crosslinking temperature, time and crosslinker ratios were determined for each crosslinker type. The swelling behaviour of the hydrogels was examined in Tris-buffer solutions at various pH at 37ºC. Swelling depending on pH was observed in the hydrogels. The pH-dependent swelling of hydrogels was strongly influenced by the functional group of crosslinker. The molecular structure of the hydrogels was studied by Fourier Transform Infrared Spectroscopy and their pore structure was investigated by using Scanning Electron Microscope.