No abstract

A variety of surface active compounds were synthesized by the quaternization of some straight chain amide derivatives with triethylamine or pyridine. Their structure FT‐IR and 1H‐NMR spectra were recorded. In addition their physical properties and corrosion prevention efficiencies were investigated. All compounds were tested with steel coupons in acidic media by the gravimetric method. As acidic media 1.5 M HCl and 1.5 M H2SO4 were used and the corrosion inhibition tests fulfilled at room temperature for 24 h. Almost all prepared cationic surfactants showed efficient inhibition around their critical micelle concentrations. The effects of HCl concentration on corrosion inhibition of some synthesized compounds were also investigated. The corrosion tests were supported by contact angle measurements.

New cationic surfactants were synthesized by the quaternization of a number of straight‐chain amide derivatives with triethylamine or pyridine. The corrosion inhibition tests of the surface‐active compounds were performed at room temperature for 24 h on carbon steel coupons in acidic media using the gravimetric method. The acidic media used were 1.5 M HCl and 1.5 M H2SO4. Almost all of the synthesized cationic surfactants showed efficient inhibition of corrosion in the test. To establish the inhibition efficiencies of the inhibitors, surface characterization studies (contact angle measurements, SEM analysis and optical profilometer images) of the metal coupons used were performed.

A series of long-chain N-arylundecanamides containing benzimidazole thioethers (2a-e) were synthesized and characterized by FT IR, 1 H NMR, and elemental analysis. The corrosion inhibitory properties of these compounds on cold rolled low carbon steel metal coupons were investigated by weight loss measurements in acidic media. Surface characterization studies of the metal coupons used were performed by contact angle measurements using the sessile-drop method. In addition, the 3D image of the metal surface was measured using an optical profilometer. The results obtained from these analyses showed that almost all of the tested compounds between 25-150-ppm concentrations in acidic media are good to excellent corrosion inhibitors with the values of percentage inhibition efficiency (η) = 77-99%.

Determination of fatty acids and some undesirable fatty acid isomers in selected Turkish margarinesThe fatty acid composition and total trans fatty acid content in 10 margarines produced in Turkey were determined by capillary gas chromatography and Fourier transform -infrared spectroscopy (FT-IR) spectroscopy. The fatty acid composition ranged as follows: saturated fatty acids, C16:0 (palmitic) 11.3 to 31.8% and C18:0 (stearic) 5.7 to 8.7%, monounsaturated fatty acids, C18:1 (oleic) 21.8 to 35.7% and C18:1 trans isomers 0.4 to 27.4%, polyunsaturated fatty acid, C18:2 linoleic acid 5.2 to 40.2%. Some positional isomers of C18:1 as cis-11-octadecenoic acid varied from 0.7 to 4.6% and cis-13 trace to 2.4%. The total trans fatty acid contents were between 0.9 and 32.0% when measured with capillary gas chromatography and between 0 and 30.2% with FT-IR spectroscopy. Some of the margarines analyzed contained trace amount of trans fatty acids which could not be detected by FT-IR spectroscopy.