Emulsion polymerization of vinyl neo-decanoate, a "water-insoluble" monomer

Rate and particle size data for the emulsion polymerization of vinyl neo-decanoate, where inhibitor/retarder effects are obviated through rigorous purification, can be quantitatively fitted by conventional mechanisms for particle formation and growth, even though the monomer has a very low water solubility. These mechanisms are (1) radical entry is by an oligomeric radical (z-mer) arising from aqueous-phase propagation at a critical degree of polymerization (z between I and 2 for this monomer) where the species becomes surface-active, (2) radical loss is by transfer to a species which desorbs into the aqueous phase and eventually terminates' (after reentry into another particle) rather than undergoing further propagation, and (3) particle formation is by a z-mer entering a micelle. These hypotheses are consistent with gamma relaxation data which give direct information on radical loss.