Anionic Polymerizable Surfactants from Biobased ω‑Hydroxy Fatty Acids

Biobased ω-hydroxytetradecanoic acid prepared via an efficient yeast-catalyzed ω-hydroxylation reaction was converted by a one-step reaction to the polymerizable surfactants ω-acryltetradecanoic acid (MA-1) and ω-maleate tetradecanoic acid (MA-2). MA-1 is a single polar-headed surfactant, whereas MA-2 is a bolaamphiphile with carboxylic acid polar groups at both chain ends. MA-1 gave a distinct critical micelle concentration (cmc) at 253 mg/L, whereas for MA-2, the surface tension decreased monotonically and a distinct cmc was not observed even up to 1800 mg/L. Experimental determination of the reactivity ratios for MA-1 and MA-2 with styrene showed that for MA-1 copolymers that approximate random structures were formed while MA-2 tends to form copolymers with an alternating nature. Emulsion polymerizations conducted with varying amounts of MA-1 and MA-2 (1–10 wt % with respect to styrene) gave colloidally stable latexes with particle sizes ranging from 52 to 155 nm. In emulsion polymerizations using either MA-1 or MA-2 at more than 5 wt % to monomer, a linear increase in latex particle volume with conversion was observed and the particle number remained constant, establishing that the polymerizations proceeded without significant aggregation or secondary particle nucleation. Potentiometric titration and ¹H NMR were used to measure MA-1 and MA-2 conversions during polymerization as well as how the surfactants were distributed between the particle surface, aqueous phase, and particle interior. Observed differences were rationalized based on the comparative structures of MA-1 and MA-2 and their corresponding partitioning behavior