Hydroxypropyl Cellulose as an Efficient Corrosion Inhibitor for Aluminium in Acidic Environments: Experimental and Theoretical Approach

Abstract

The adsorption and inhibition performance of hydroxypropyl cellulose (HPC) on aluminium corrosion in 0.5 M HCl and 2 M H2SO4 were investigated at 30–65 °C using potentiodynamic polarization, gravimetric measurement and quantum chemical computation technique respectively. Potentiodynamic polarization results confirmed that HPC acted as a mixed-type inhibitor in both aggressive solutions with a more dominant anodic effect. Results of gravimetric measurement revealed that HPC displayed significant regulatory action on the corrosion of aluminium within the condition studied. Also, aluminium was observed to exhibit higher resistance to dissolution in sulphuric compared to hydrochloric acid. Also, improvement in inhibition efficiency was recorded with an increase in the concentration of inhibitor, but its sustainability was altered with an increase in temperature. The trend of adsorption mechanism proposed was based on the relationship between temperature and inhibition efficiency and computed results of the energy of activation. The adsorption of HPC molecules onto aluminium surface followed the Langmuir adsorption isotherm. Quantum chemical calculations through the aid density functional theory were used to reveal the adsorption strength attractiveness of HPC molecules towards aluminium surface.