Hydrogels of sodium alginate based copolymers grafted with sodium-2-acrylamido-2-methyl-1-propane sulfonate and methacrylic acid for controlled drug delivery applications

Novel sodium alginate based hydrogels were prepared by grafting the binary mixture of methacrylic acid and sodium-2-acrylamido-2-methyl-1-propane sulfonate on to sodium alginate (SA) with N,N'-methylenebisacrylamide (MBA) and ammonium persulfate (APS) as crosslinker and initiator respectively. The resultant SA-g-poly(AMPSNa-co-MAA) hydrogels were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Thermo Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). The results indicated that an increase in the amount of sodium-2-acrylamido-2-methyl-1-propane sulfonate, swelling capacity was found to increase. The effects of temperature, pH and inorganic salt on the swelling behavior of the hydrogels were investigated. The pH reversibility behavior at pH levels of 1.0 and 9.0 indicated great potential of this hydrogel as a candidate system for controlled drug delivery.