Abstract
The corrosion inhibition of mild steel in hydrochloric acid solution in the presence of three different molecular weights of polyvinyl alcohol (PVA) designated as PVA-I, PVA-II, and PVA-III corresponding to 14,000, 72,000, and 125,000 g mol-1, respectively, was investigated using electrochemical impedance spectroscopy, linear polarization resistance (LPR), and potentiodynamic polarization techniques at 25°C. It was found that PVA of different molecular weights inhibited the corrosion of mild steel in the acid environment. Inhibition efficiency (η%) increases with increase in concentration of the polymers. LPR measurements clearly show that inhibition efficiency increases with increasing molecular weight in the order PVA-III > PVA-II > PVA-I. Polarization curves indicate that PVA functions as a mixed inhibitor affecting both the anodic metal dissolution and cathodic hydrogen evolution partial reactions of the corrosion process. The experimental data obtained fitted well into Langmuir adsorption isotherm model. Physical adsorption mechanism is proposed from the thermodynamic (free energy of adsorption) parameters obtained.
| Original language | English |
|---|---|
| Pages (from-to) | 1181-1190 |
| Number of pages | 10 |
| Journal | Journal of Dispersion Science and Technology |
| Volume | 35 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2014 |
Keywords
- Acid corrosion
- corrosion inhibition
- mild steel
- molecular weight
- polyvinyl alcohol
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Polymers and Plastics
