Hydrolysis and biodegradation studies of surface‐active esters

• Published in: Journal of Surfactants and Detergents
• Main Authors: Stjerndahl, Maria, van Ginkel, Cornelis G., Holmberg, Krister
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2003
• Subjects: Alka; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1007/s11743-003-0276-z; https://onlinelibrary.wiley.com/doi/full/10.1007/s11743-003-0276-z

Abstract Base‐catalyzed hydrolysis, biodegradation, and enzyme‐catalyzed hydrolysis of a series of four monoesters of tetra(ethylene glycol) have been investigated. The surfactants varied in substitution on the α‐carbon of the acyl chain, from no substitution, to 2‐methyl, to 2‐ethyl, and on to 2,2‐dimethyl. All surfactants were based on C 8 ‐acids except the methyl‐substituted, which was based on a C 7 ‐acid. The hydrolysis was investigated using 1 H nuclear magnetic resonance. The surfactants showed a pronounced difference in stability with respect to type of substitution in the vicinity of the ester bond. In alka‐line hydrolysis the most significant difference in reactivity lay between the surfactant with an ethyl group and the surfactant with a methyl group in the α‐position of the acyl chain. However, in the biodegradation studies these surfactants broke down at almost exactly the same rate as the nonsubstituted surfactant. In the biodegradation test, the disubstituted surfactant deviated considerably. Two lipases, from Mucor miehei (MML) and Candida antarctica B (CALB), were used in the enzyme‐catalyzed hydrolysis. The surfactant with no substitution was found to hydrolyze much faster than the other surfactants, and the hydrolytic activity of MML, but not CALB, increased in the presence of surfactant micelles.