Isolation of Cinnamaldehyde and its application as a green corrosion inhibitor for A03081 alloy in 2.0 M HCl solution: Theoretical, Electrochemical and Thermodynamics studies

Isolation of Cinnamaldehyde from Cinnamon was executed successfully. The structure of Cinnamaldehyde was confirmed using FTIR, 1H NMR, 13C NMR and mass spectroscopies. Chemical, electrochemical and thermodynamic measurements were employed to study Cinnamaldehyde behavior as a corrosion inhibitor for aluminum in acids. The results showed that Cinnamaldehyde molecules tend to adsorb on the aluminum surface covering it from the attacking acidic medium, with %IE = 93.24% after 24 h. Temkin adsorption isotherm is fitted with the results excellently, that the adsorption process was considered spontaneous and predominantly physical, with ΔG°ads values reached -35 kJ.mol-1. Thermodynamic parameters were estimated and discussed. SEM analysis and quantum study were conducted to support the inhibition capability of the extract.