Emulsion polymerization of acenaphthylene. I. A study of particle nucleation in water phase and in aqueous emulsions

As the first phase in the study of the emulsion polymerization of acenaphthylene (AcN), the oligomerization kinetics of the in-aqueous-phase soluble portion of the AcN monomer was investigated. The reactions were carried out in the absence and presence of anionic emulsifiers. The monomer disappearance rate was followed by ultraviolet (UV) spectroscopy and spectra were established for these species. It was found that aqueous phase AcN oligomerized with K₂S₂O₈ initiator at 50°C to yield SOK⁺ -ended oligo -AcN species which showed a UV hypsochromic shift in polar solvents. The oligomerization had a second-order dependence on monomer concentration. The presence of sodium oleate (SO) and sodium dodecyl sulfate (SDS) emulsifiers at below and above their critical micelle concentrations decreased the rate constant of the aqueous phase oligomerization. These observations led to the suggestion of a mixed micellization concept in the particle nucleation mechanism.