Temperature and pH sensitive ionic hydrogels based on new crosslinkers

New crosslinkers were synthesized from reaction of melamine with acryloyl and methacryloyl chloride in the presence of 1-methyl-2-pyrrolidone as a solvent and triethyl amine as acid acceptor. The chemical structures of the prepared crosslinkers were elucidated from FT-IR, 1H-NMR and 13C-NMR analyses. Linear 2-acrylamido-2-methyl-1-propane sulfonic acid and methacrylic acid (AMPS/MAA) copolymers were prepared and their viscometric properties in aqueous solution were investigated. Different weight percentages of the prepared crosslinkers were used as crosslinking agent (AMPS/MAA) to prepare ionic copolymers using ammonium persulfate as initiator. The percentage of crosslinkers was varied from 0.5 to 4 wt%. The swelling behaviors of crosslinked AMPS/MAA gels in deionized water were measured at different pH and temperatures. All AMPS/MAA copolymers exhibit faster deswelling rate at 50°C except for the copolymer containing 0.9 (mol ratio) AMPS.