Mechanism of Formation of the Protective Films on Steel by Volatile Compounds of Rapeseed Cake

Abstract

The mechanism of formation of protective films on the steel surface in the course of its treatment by the extract of rapeseed (Brassicaceae family) cake regarded as a volatile corrosion inhibitor and its component composition are experimentally determined and theoretically substantiated. The dynamics of changes in the component composition of volatile compounds in the 2-propanol extract of rapeseed cake is studied by the methods of gas chromatography, mass spectrometry, and IR-spectroscopy. The influence of individual components on the corrosion behavior of steel under the conditions of periodic condensation of atmospheric moisture is investigated. It is shown that the main components of the 2-propanol extract responsible for its anticorrosion efficiency are aldehydes, ketones, and glycosides. A model of the structure of protective films is proposed.In the course of transportation and conservation, metal products are damaged by corrosion, which decreases their user and export values. Hence, it is necessary to guarantee their temporary anticorrosion protection in order to preserve their quality and the outward appearance of the surfaces under the atmospheric conditions [1,2]. In this case, the most efficient and (sometimes) the only possible method for the protection of metals is given by the volatile inhibitors. At present, the production of volatile inhibitors of the atmospheric corrosion is absent in the Ukraine and the domestic market is filled with extremely expensive imported products, sometimes of very low quality.Due to the insufficient supply of these inhibitors, the increase in the cost of raw materials used for their production, and a permanent strengthening of the sanitary-hygienic requirements to the means of corrosion protection, it is necessary to create new inhibiting compositions based on the natural resources. Thus, the organic compounds obtained from ecologically safe and annually renewed vegetable raw materials seem to be quite promising for the development of new volatile inhibitors of the atmospheric corrosion [3-6].In [7,8], it is shown that the wastes of the production of oil from rape seeds (Brassicaceae family) may serve as a source of natural organic compounds. Moreover, the chemical compositions of the volatile compounds of 2-propanol extract of rapeseed cake and the inhibiting efficiency of this extract were investigated. However, we do not know the compounds appearing in the composition of this extract and responsible for its inhibiting efficiency. Therefore, it is necessary to study the specific features of the mechanism of formation of protective films formed from the vapors of the extract of rapeseed cake on the steel surface and to determine the compositions of these components.

Experimental and Theoretical Investigations of Anti-Corrosive Properties of Thymol

“…However, as a result of their high cost and increasing awareness of health and ecological risks, attention is being drawn towards finding highly efficient, cheaper and non-toxic inhibitors. The present trend in research on environmental friendly corrosion inhibitors is concentrating on products of natural origin due principally to their low cost and eco-friendliness [5][6][7][8][9][10].…”

“…Thus, it was shown that the wastes of the production of oil from rapeseeds (Brassicaceae family) [6,7], hop cones (Humulus lupulus family), pomaces of grapes (Vitis vinifera family) [8], wood bark oil [9], and thyme [10,11] can be a source of natural organic compounds for the preparation of VCI. The plant extract is a mixture of various components, which results in the complex inhibitive mechanism.…”

A comprehensive study of grape pomace extract and its active components as effective vapour phase corrosion inhibitor of mild steel

“…Over the recent years, the use of naturally occurring substances of plant origin, otherwise called "green corrosion inhibitors" has received much more attention because they are incredible sources of natural organic compounds, which are environmentally acceptable, inexpensive, readily available and renewable sources of materials [9][10][11][12][13].…”

Self-assembled monoterpenoid phenol as vapor phase atmospheric corrosion inhibitor of carbon steel

“…With the aim of improving the stability of the organic protective films, treatments other than adsorptive films formation were developed. In continuation of our work, some plant extracts have been studied as effective volatile corrosion inhibitors of steel namely In continuation of our work, some plant extracts have been studied as effective volatile corrosion inhibitors of steel namely Rapeseed cake, Hope Cones, Brushes and skins of grapes and Lavanda, Artemisia extracts [10][11][12][13][14][15]. Through these studies, it is agreed that the inhibition performance of plant extract is normally ascribed to the presence in their composition of complex organic species such as aldehydes, terpenoids, glycosides, nucleosides, ketones and aldehydes, saturated and unsaturated fatty acids.…”

“…Through these studies, it is agreed that the inhibition performance of plant extract is normally ascribed to the presence in their composition of complex organic species such as aldehydes, terpenoids, glycosides, nucleosides, ketones and aldehydes, saturated and unsaturated fatty acids. The inhibition of mild steel corrosion by the studied species of plant raw materials [10,11] is probably attributed to the presence of most important compounds such as a monoterpenoid phenol -Carvacrol.…”