"Caterpillar-like" Multibranched Alcohol Ether Surfactants Derived from Isooctanol

Isooctanol is synthesized from n-butanol via the Guerbet reaction; however, its surfactant derivatives show insufficient surface activity owing to their short alkyl chains. Herein, we develop a precise 1,2-epoxybutane grafting strategy to extend the alkyl skeleton and increase molecular branching, thereby synthesizing novel "caterpillar-like" multibranched extended alcohol ether surfactants. After systematic process optimization, two multibranched alcohols (C8B1-OH and C8B2-OH) with purity exceeding 95.0% were obtained. Three tailored surfactants (C8E6, C12E9, and C16E12) were then synthesized by ethoxylation, and their chemical structures were fully characterized. Systematic performance evaluations demonstrated that these as-prepared surfactants exhibited superior overall performance relative to the benchmark commercial nonionic surfactant AEO9. Specifically, C12E9 and C16E12 exhibited lower γCMC (surface tension at the critical micelle concentration) values, while all three surfactants showed ultrafast defoaming performance, with defoaming times shorter than 75 s, remarkably outperforming AEO9. The optimized C16E12 exhibited the best wetting performance, achieving a low contact angle of 14.6° on brass surfaces within 30 s at a concentration of 1 mM, and its emulsifying ability was nearly twice that of the unmodified short-chain counterpart C8E6. Benefiting from the recyclability of the isooctanol feedstock, this synthetic route enables sustainable resource utilization and complies with the high-efficiency and eco-friendly criteria of green chemistry. This work establishes a facile synthetic route for novel "caterpillar-like" multibranched surfactants and offers new insights into their scalable industrial applications.