Synthesis, surface active properties and applications of cationic gemini surfactants from triethylenetetramine

Abstract

The 2-Alkyl-1-diethylenediaminimidazoline based Gemini amphiphiles were successfully synthesized in a two step methodology. In the first steps, triethylenetetramine was reacted with fatty acids namely viz. caprylic acid, lauric acid, myristic acid & palmitic acid to get the corresponding amides which on continuous heating results into 2-alkyl-1-diethylenediaminimidazoline. These imidazolines in second step were reacted with 1, 6-dibromohexane to form targeted cationic Gemini surfactants. The chemical structure of compounds was confirmed by means of FTIR, ¹H-NMR and 13C-NMR spectroscopy. The effect of alkyl chain length of synthesized surfactants on the basic characteristics such as surface tension, foaming, emulsifying capability, lime soap dispersing power and wetting were studied. These new surfactants were investigated for their biodegradability, anticorrosion and antimicrobial activity. They have capacity to reduce surface tension of water from 71.8 mN.m⁻¹ to 27.42 mN.m⁻¹. The 2-octyl-1-diethylenediaminimidazoline based Gemini surfactant (GSCTDH) showed good biocidal activity against gram positive Bacteria Bacillis subtilis (16.57 mm) & Staphylococcus aureus (19.46 mm). The 2-dodecyl-1-diethylenediaminimidazoline based Gemini surfactant GSLTDH has good inhibition against gram negative bacteria Pseudomonas aeruginosa (14.33 mm) and Escherichia coli (18.31 mm). The biodegradation results allowed classification of synthesis compounds as readily biodegradable. The Gemini surfactant GSCTDH has 96.71% inhibition efficiency against carbon steel. It can be used as an anticorrosion agent.