Synthesis and biodegradation studies of gamma irradiated electrically conductive hydrogels

Poly(acrylamide-aniline)-grafted gum ghatti [Gg-cl-poly(AAm)] conducting hydrogel was prepared via 60Co γ-irradiation using N, N′-methylene-bis-acrylamide as a cross linker. The effects of the reaction conditions (viz. gamma dose, monomer, solvent and cross linker concentration) were investigated on the degree of swelling of Gg-cl-poly(AAm). Results showed that optimum reaction conditions for maximum percentage swelling were 10 ml of solvent, 1.08 mol/L of monomer concentration, 0.324 × 10−1 mol L−1 of crosslinker concentration and 1.5 kGy of total dose. The semi-interpenetrating network (Semi-IPN) was converted into an IPN through the impregnation of poly(aniline) chains followed by doping with HCl. The influence of dopant concentration on the conductivity of synthesized hydrogel was investigated. Different physical properties of the synthesized hydrogel were also studied. The candidate polymers were characterized using different techniques such as X-ray diffraction and thermogravemetric analysis techniques. The mechanism of graft copolymerization via 60Co irradiation was discussed. Biodegradation studies of the synthesized hydrogels were carried out using a soil burial test. IPN showed better degradation efficiency than semi-IPN. Weight loss of semi-IPN and IPN was 68% and 78%, respectively, in 60 days. Different degradation stages were studied using FTIR and SEM techniques.