Colloidal-chemical and inhibiting properties of N-(2-hydroxyethyl)alkylamines

Abstract

Effect of the pH of the medium on colloidal-chemical characteristics of reagents from the N-(2-hydroxyethyl)alkylamine series and the effect of these reagents on the corrosion behavior of 0.5 KP steel in 1 M HCl were studied. The corrosion inhibition mechanism was found.N-(2-Hydroxyethyl)alkylamines (HEAs) are known as intermediate compounds in synthesis of poly(oxyethylene)alkylamines RN(CH 2 CH 2 OH) m (CH 2 CH 2 -OH), which are strong surfactants [1]. Lower homologs of the HEA series have been suggested as fl occulants for purifi cation of neutral and weakly acidic wastewater to remove Cu(II) ions [2]. However, evidence about properties and applications of these reagents is scanty and nonsystematic.Here, we proceed with our study [3] of physicochemical properties of N-(2-hydroxyethyl) alkylamines of general formula RNHCH 2 CH 2 OH, where R = C 8 H 17 -C 16 H 33 and examine the infl uence exerted by the pH of the medium on the surface-active and functional characteristics of compounds belonging to the given homologous series.EXPERIMENTAL N-(2-Hydroxyethyl)alkylamines were produced by the method described in [3]. The content of the main substance in the samples obtained was no less than 96% The surface tension at the interfaces between an aqueous solution of HEAs and air and a solution of HEAs in 0.1 M HCl and air was measured by the stalagmometric method [4].Corrosion tests were performed on samples fabricated from 0.5 KP steel. Gravimetric tests were made with planar 30 × 20 × 2 mm samples, and electrochemical studies, on planar electrodes with a working surface area of 1 cm 2 . The samples were prepared for the study by cleaning with fi ne emery paper, degreasing with ethanol, and rinsing with distilled water. The gravimetric tests were made on the whole surface of the samples, whereas in electrochemical studies, all nonworking surfaces were insulated with a paraffi n-rosin mixture. The study was performed in 0.1 M HCl (chemically pure grade). The working electrolytes were prepared from distilled water. The protective effect of compounds was evaluated by the gravimetric method [5].The corrosion rate of steel, ρ, was calculated by the formula (1) where Δm is the loss of mass by a sample during tests (g); S, surface area of the sample (m 2 ); and τ, test duration (h).The protective effect Z (%) and the inhibiting effect γ were determined by the formulas

Identification and Application of Corrosion Inhibiting Long- Chain Primary Alkyl Amines in Water Treatment in the Power Industry

“…Others multifunctional anti-corrosive and anti-scaling formulations based on alkyl amines were described in several publications or patents [12][13][14][15][16][17][18]. To prevent adsorption of alkyl amines on the glass surface, spiked water samples of 10 mg L -1 to 100 mg L -1 of Primene JM-T™ were prepared and stored at ambient temperature in a 1 L polypropylene (PP) volumetric flasks (Kartell, Noviglio, Italy).…”