Synthesis of Crosslinked Networks of Gum ghatti with Different Vinyl Monomer Mixtures and Effect of Ionic Strength of Various Cations on its Swelling Behavior

A series of pH, temperature, and electrical stimulus sensitive novel hydrogels of Gum ghatti (Gg) with vinyl monomer mixtures of acrylamide (AAm) with acrylic acid (AA), acrylonitrile (AN), and methacrylic acid (MAA) using potassium persulphate-ascorbic acid redox pair as an initiator and N,N'-methylene-bis-acrylamide (MBA) as a crosslinker was synthesized using a free radical polymerization process. Initially, different reaction parameters for the graft copolymerization and crosslinking of Gum ghatti with AAm and MBA were optimized. Afterwards, optimization of AA, AN, and MAA in combintation with preoptimized AAm was carried out. Synthesized products were characterized by FT-IR, SEM, XRD, and TGA/DTA/DTG. Swelling behavior of hydrogels was investigated in deionized water as a function of time, temperature, and pH of swelling medium. Moreover, hydrogels have been found to exhibit cationic charge-dependent swelling in different salt solutions of Na+, Ba2+, Fe3+, and Sn4+. The order of swelling was found to be Na+ > Ba2+ > Fe3+ > Sn4+.