Study Of PH Sensitive Hydrogels Retaining High-strength Over A Wide PH Range

In this study, we synthesized a novel pH-sensitive high-strength hydrogelP(AAPBA-co-VDT-co-OEGMA) by copolymerizing two hydrogenbonding-motifs-containing monomers,3-acrylamidophenylboronic acid(AAPBA),2-vinyl-4,6-diamino-1,3,5-triazine(VDT) in the presence of Initiator2-hydroxy-4-(2-hydroxyethoxy)-2-methyl-propiophenone (IRGACURE-2959) andcrosslinker N,N-methylenebisacrylamide(MBAA) through hydrophilic optimizationof monomer oligo(ethylene glycol) methacrylate.FTIR measurement proved thesuccessfully photopolymerization of the hydrogels. The intermolecular hydrogenbondings originating from4,6-diaminotriazine(DAT) residues were shown tosignificantly enhance both the tensile and compressive strengths at neutral and acidicpH. Whereas phenylboronic acid(PBA), which has a propensity to formhydrogen-bonded dimers at acidic pH, can provide high-strength in neutral andalkaline conditions. So the gels will remained robust and pH sensitive over a wideacid-alkalin pH range. By changing the mass ratio of the monomer feed ratios andinitial concentration, we can obtain the hydrogel with different mechanical andswelling properties. The concept of double hydrogen bonding network will extendthe application range of pH sensitive hydrogels.