Synthesis and physico-chemical studies of glycine betaine derivatives

Design of new surfactants is of considerable interest in order to obtain materials with specific physico-chemical properties for targeted applications. Among them, quaternary ammonium surfactants are widely employed in pharmaceutical and cosmetic industries.
Unfortunately, as a consequence of their widespread use and strong resistance to biodegradation, those chemical surfactants may persist in wastewater treatment systems at relatively high concentrations and can cause a disturbance of the ecological equilibrium.
In this context, glycine betaine based surfactants are of increasing interest today thanks to their higher biodegradability and low environmental impact. For example, alkylbetaines and alkylamidobetaines are produced on the industrial scale and are used as amphoteric surfactants less irritating compared to sodium dodecylsulfate (SDS) in cosmetics.

In this study, new surface-active agents based on glycine betaine and issued from the green chemistry are synthesized. Very simple synthetic methodologies led to different betaine derivatives (esters, thioesters, amides). Their physico-chemical properties are investigated in order to give insights about the key parameters to take into account for the formulation of betaine derived compound preparations for cosmetic or pharmaceutical purposes.