Protection of carbon steel surface in extreme environment using polymer mixture: effects of time, inhibitor concentration, mixing ratio and synergy

Hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) were mixed in the varying ratios of 1:1 and 1:3 respectively and used to formulate inhibitor systems for corrosion inhibition studies on carbon steel surface induced in 1.0 M H 2 SO 4 solution. The performance of formulated inhibitor systems was assessed using weight measurement, potentiodynamic polarization technique at 28 − 65 °C and theoretical computation respectively. Weight loss measurement result revealed that corrosion resistance of the formulated inhibitor systems was dependent on time, mixing ratio, inhibitor concentration and temperature. Thus, the optimum inhibition performance obtained was from the combination of HPMC and PVA with ratio of 1:1. Also, the adsorption characteristics recorded was attributed to formation of protective complex thin film on the carbon steel surface via Temkin adsorption isotherm. The temperature and inhibition efficiency relations obtained supported physical adsorption mechanism proposed. In addition, potentiodynamic polarization result revealed that action of inhibitor systems modified both partial electrochemical reaction processes and also retained the mixed mode function in its operation. Density function theory revealed the chemistry reactivities of inhibitor system in aqueous phase whereas molecular dynamic simulation interpreted the real experimental condition of metal surface in extreme electrolytic solution in the presence of inhibitor.