Antibacterial materials: structure-bioactivity relationship of epoxy-amine resins containing quaternary ammonium compounds covalently attached

Bifunctional aminoalkyldimethylpropylammonium salts (N-(3-aminopropyl)-N,N-dimethylpentylammonium chloride, N-(3-aminopropyl)-N, N-dimethyloctylammonium chloride, N-(3-aminopropyl)-N,N-dimethyldecylammonium chloride, N-(3-aminopropyl)-N,N-dimethyldodecylammonium chloride) are synthesized and their structure-dependent antibacterial effect against Gram-negative Escherichia coli and Gram-positive Lactococcus lactis is investigated. To this end, resins prepared from bisphenol A diglycidyl ether (2,2-bis[4-(glycidyloxy)phenyl]propane) and diethylenetriamine (2,2'-diaminodiethylamine) as matrix and the bifunctional aminoalkyldimethylpropylammonium salts in a ratio of 6 mol% compared to epoxy components are used. A dependence of antibacterial effect on alkyl chain length of the quaternary ammonium compounds is observed for both species. Furthermore, resins with N-(3-aminopropyl)-N,N-dimethyldecylammonium chloride in varying concentrations up to 16 mol% for both organisms show a concentration-dependent antibacterial effect of the quaternary ammonium salt. The antibacterial materials are characterized by differential scanning calorimetry, infrared spectroscopy and rheological studies. (C) 2013 Society of Chemical Industry