Corrosion inhibition of mild steel in 1 M Hcl using synthesized eco-friendly polymer composites

M.Tech. (Metallurgy)Abstract: In this work, two polymer composites namely PBSLP and PBSLH were synthesized and characterized by FTIR, NMR, XRD, SEM, CHNS and TGA. The results revealed that the formed polymer composite were graft polymer composites. The two synthesized polymer composites were investigated as corrosion inhibitors for MS in 1 M HCl. The corrosion inhibition characteristics including, corrosion rate, corrosion inhibition efficiency, and inhibitor adsorption to the metal surface were studied with gravimetric and electrochemical studies. The gravimetric studies revealed that adsorption of the polymer composites to the MS surface were both physisorption and chemisorption although physisorption appeared to be the more dominant process. Moreover, both polymer composites obeyed Langmuir isotherm. Electrochemical studies were also used to characterize that inhibitory mechanism of the said polymer composites. PDP, specifically Tafel plot and VASP with used to determine the corrosion parameters while EIS was employed to determine the charge transfer characteristics during corrosion. The results indicated that PBSLP and PBSLH are both mixed type corrosion inhibitors with cathodic reaction being the most affected reaction. In addition, the charge transfer resistance during corrosion increased with the increase in concentration of inhibitors. SEM was also used to examine the morphology of MS coupons before and after exposure to corrosive, the results revealed that PBSLP and PBSLH reduce corrosion of MS by forming a film on MS surface