Synthesis and Characterization of Polyglycerol-based Surfactants

Abstract

Polyglycerol-based surfactants have gained recognition as a renewable and safe alternative to polyethylene glycol-based surfactants, which are derived from fossil resources. Polyglycerol esters have a complex and polydisperse structure upon synthesis, which makes it difficult to pinpoint which characteristic of the compound is responsible for a certain property. It is therefore desirable to obtain monoesters as this would facilitate a more accurate comparison of the performance of different surfactants. To promote monoester formation, optimization of the synthesis was performed by fine-tuning the reaction conditions. The synthesized polyglycerol esters were characterized using various techniques. The results indicated that a higher molar ratio of polyglycerol to fatty acid promoted monoester formation. However, it is yet to be confirmed whether one-phase synthesis (in solvent) results in a higher monoester content than two-phase synthesis (solvent-free). The surfactants were also tested for their cleaning efficacy. A particular formulation of PG6C10 ester performed comparably to that of Berol OX 91-6 (a polyethylene glycol-based surfactant), indicating that polyglycerol esters are a promising green alternative to fossil-based surfactants.