Antiradical activity, base-catalyzed hydrolysis and partition coefficients of some surfactants

Abstract

Antiradical activity and some environmental characteristics such as biodegradability and bioavailability of several coconut oil derived surfactants have been studied by photometry and UV–Vis absorption spectroscopy. The effects of polar group size and type were revealed using non-ionic surfactants cocamide monoethanolamine, cocamide diethanolamine, amphoteric surfactant cocamidopropyl betaine, and anionic surfactants sodium lauryl sulfate and sodium alfa olefin sulfonate. Free radical scavenging properties were examined by determination of rate constant of the reaction with hydroxyl radicals. To calculate the rate constant the competitive reaction between hydroxyl radicals and p-nitroso-N,N-dimethyl aniline was investigated. The results show pronounced antioxidant activity of surfactants. To confirm the environmentally friendly character of mentioned surfactants the biodegradability and accumulation were studied using base-catalyzed hydrolysis and partition coefficient between n-octanol/water layers. The obtained results show that type of head group and the carbon chain structure have major effect on these properties.