Green corrosion inhibitors

Abstract

The corrosion inhibiting possibility examination of extracts obtained from fruits of rose hip and horse chestnut was investigated. Rose hip extracted at different temperatures exhibited different corrosion inhibiting effect. Rose hip obtained at 40oC did not show any inhibiting effect in neutral pH medium, while in acidic media it expressed moderate protective impact (up to 55%) for steel and mild corrosion inhibiting impact for zinc (39%), while for aluminium and copper it did not have any inhibiting effect. Rose hip obtained at 25oC exhibited significant inhibiting effect for steel (up to 62 %) and even better for zinc (up to 72%) in neutral media. For aluminium and copper neither of Rose hip extracts showed any inhibiting effect. The Horse chestnut extract exhibits moderate to significant inhibiting effect for steel (up to 55%) and zinc (up to 60%) in neutral media. In addition to this, because of the complex chemical composition of these fruit extracts, some further electrochemical investigation is suggested, aimed to determine a single component inhibitive effect. Firstly, as one of prevailing components, tannins are examined. Linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) were used as a testing techniques.