Affiliation:
1. Department of Chemistry,P.K. Roy Memorial College (Affilated to Binod Bihari Mahto Koyalanchal University), Dhanbad-826004, India
2. Department of Applied Chemistry, Indian Institute of Technology (Indian School of Mines), Dhanbad-826004, India
Abstract
The inhibitory effect of guar gum (GG) as a green inhibitor has been studied using a variety of
methodologies, including weight loss, thermometric studies at 30-60 ºC. The potentiodynamic
polarization, electrochemical impedance spectroscopy (EIS) and scanning electron micrographs have
been found to the good inhibitor for mild steel corrosion in H2SO4 (pH = 1) medium. Guar gum fits to
the Langmuir adsorption isotherm when it adsorbs to metal surfaces. It has also been investigated how
adding halides (KCl, KBr and KI) will affect the process. The findings demonstrated that guar gum
concentration increased with inhibition efficiency (I%). All of the concentrations of guar gum are
shown to be promoted by the inhibitive impact of guar gum in addition to halide ions. The trend Cl– <
Br– < I– has been seen to improve inhibition efficiency (I%) and the extent of surface coverage (θ),
which suggests that the electronegativity and radii of the halide ions play a significant role in the
adsorption process. According to polarization curves, guar gum functions as a mixed-type inhibitor.
The outcomes of gravimetric studies and electrochemical procedures were in good agreement. Based
on thermodynamic characteristics and a comparison of the FT-IR spectra of pure and metal surface
product, a thorough adsorption of the inhibitor molecules on the mild steel surface was proposed.
When the synergism parameter (SI) was analyzed, it is found to be greater than unity, indicating that
synergism alone is responsible for the increased inhibitory efficiency caused by the addition of halides.
Publisher
Asian Journal of Chemistry