Performances of Alkaloid Extract from Rauvolfia macrophylla Stapf toward Corrosion Inhibition of C38 Steel in Acidic Media

Autor: Armel Megha Nouteza, Emmanuel Ngameni, Martin Pengou, Bertrand Ngouné, Charles Péguy Nanseu-Njiki
Rok vydání: 2019
Předmět:
Zdroj: ACS Omega, Vol 4, Iss 5, Pp 9081-9091 (2019)
ISSN: 2470-1343
DOI: 10.1021/acsomega.9b01076
Popis: Alkaloid extract from Rauvolfia macrophylla Stapf (AERMS) was studied as the corrosion inhibitor for C38 steel in 1 M HCl and 0.5 M H2SO4 using electrochemistry and surface analysis. The corrosion inhibition was efficient and proceeds via adsorption of AERMS on the steel surface due to the active functional groups present in the molecules. AERMS acts as a mixed inhibitor in HCl and as a cathodic inhibitor in H2SO4. In H2SO4 corrosive medium, the presence of iodides improves the adsorption of the alkaloid molecules by reducing the surface charge of the electrode and thus substantially decreases the corrosion rate. Two pure alkaloids (tetrahydroalastonine (THA) and perakine (PER)) were quantitatively isolated from AERMS, and their anticorrosive properties for C38 steel in 1 M HCl and 0.5 M H2SO4 were evaluated. THA showed the highest efficiency while the performance of PER was less important compared to the extract. This confirms that the efficiency of AERMS was the result of the complementary action of the chemical compounds present in the extract.
Databáze: OpenAIRE