Synthesis and properties of sodium fatty acyl lactylates

Sodium fatty acyl lactylates (Cn lactylates), which are a class of biomass-based surfactants, were synthesized from fatty acids and lactic acid via a two-step reaction. The equilibrium surface tensions, dynamic surface tensions, and application performances of synthesized surfactants with various hydrophobic chain lengths were studied and compared. With the increasing of alkyl chain length, the Cn lactylates exhibited better surface activity along with excellent foaming and emulsificationproperties, and the wettability on paraffin film and stain removal ability on carbon black-stained cloth improved. Moreover, C10 lactylate showed superior antibacterial ability against E. coli, whereas C12 lactylate demonstrated the best wetting property on canvas sheets and the best decontaminability on sebum-soiled cloths. These results showed that the properties of Cn lactylates can be tuned by modifying the chain length.