Toxic contaminants in polyoxyethylene alkylamines

Model and technical-grade alkylamines were oxyethylated in the presence of NaOH and water and the amounts of oxirane, 1,4-dioxane and ethylene glycol were determined. Significantly higher levels of toxic contaminants are formed in the presence of water. The two-step synthesis permits the levels of toxic contaminants to be decreased. The lowest amounts of these toxic components are observed in N-alky-N,N-di(hydroxyethyl)amine obtained without any catalyst. The two-step synthesis also makes it possible to narrow the polyoxyethylene chain distribution. The toxic contaminants can be effectively stripped from the reaction mixture by nitrogen purging at elevated temperature.