Synthesis and characterization of surfactants via epoxidation of tall oil fatty acid

The synthesis and characterization of novel surfactants derived from tall oil fatty acid methyl esters are presented. The tall oil fatty acid methyl esters, which mainly contain methyl oleate, were converted to 9,10‐epoxy derivatives and further transformed to the 9 (or 10) polyethylene glycol (PEG) ethers. Compounds with three different monomethylated PEG chain lengths with molecular weights of 350, 550, and 750, corresponding roughly to 7, 11, and 16 ethylene oxide units, were prepared. Surfactants were formed at an 89% overall yield from tall oil fatty acid. Cloud points were 46, 63, and 84°C, respectively, and surface tensions at the CMC (2.0, 1.0, and 0.4 mM, respectively) varied from 33 to 38 mN/m. Equilibrium surface tension and reflectometry measurements were made and results were similar to those of conventional long alkyl chain PEG surfactants. Results of the tensiometry and reflectometry measurements showed that the surfactants aligned better at the air‐water interface than conventional surfactants. The adsorption properties for the three surfactants were similar to those of polyoxyethylene glycol alkyl ethers.