Enhancement of corrosion inhibition efficiency of sodium alginate via grafting with polyacrylamide

Copolymerization of sodium alginate (SAG) with polyacrylamide (PAC) was successfully achieved using microwave assisted polymerization technique. At 240 mg/100 mL sodium alginate on its own gave an inhibition efficiency of 64%, while its grafting with polyacrylamide the efficiency reached 86%. Statistical analysis revealed a highly significant difference in inhibition efficiency between SAG and SAG-g-PAC. SAG-g-PAC data obeyed four adsorption isotherm models, namely Langmuir, Temkin, Flory???Huggins, and kinetic model of El-Awady isotherm, while SAG data obeyed only Langmuir model. Scanning electron microscopy images revealed the smoothness and homogeneity of SAG-g-PAC adsorption on the mild steel surface.