Hyperbranched Polyamidoamine Surfactants: Synthesis, Characterization and Evaluation as Biocides

Abstract

AbstractDifferent generations of cationic hyperbranched quaternary ammonium polyamidoamine dendrimers (PAMAM) with methyl ester end group (G-0.5, G 0.5, G1.5 and G 2.5) were synthesized. Preparation of these dendrimers was carried out via alternative steps of an aza Michael addition reaction (of piperazine as core center molecule) and amidation reaction by ethylene diamine. Each aza Michael addition step was followed by a quaternization step using alkyl bromide with different chain length (4, 8 or 12) carbon atoms. The chemical structures of the prepared dendrimers were confirmed using FTIR, 1H-NMR spectra and elemental analysis for two generations as representative compounds. Also their surface activity has been studied and their surface parameters including surface and interfacial tension, emulsification power, critical micelle concentration, effectiveness, efficiency, maximum surface excess and minimum surface area were determined. The prepared quaternized dendrimers were tested as antimicrobial agents against different strains of bacteria, yeast and fungi. The results showed a significant antimicrobial efficacy of the synthesized surfactants.