The manufacture and polymerization of stable n-butyl cyanoacrylate (BCA) miniemulsions
were achieved in the presence of dodecylbenzenesulfonic acid (DBSA). This surfactant, by releasing protons
at the interface, slows down the interfacial anionic polymerization of n-BCA through (reversible)
termination. Preliminary emulsion experiments showed that adequate DBSA/monomer ratios and stirring
rates are required to avoid the generation of long polymer chains through uncontrolled polymerization.
By sonicating the original mixture to produce a miniemulsion, a fair control of oligomer generation is
exerted. In all experiments, however, the final oligomer distribution is mainly composed of three to five
units, with the equilibrium value imposed by interfacial polymerization/depolymerization events. As a
consequence, particles quickly destabilize by Ostwald ripening of the partly water-soluble hydroxylated
oligomers. Decreasing the acid content after sonication by adding hydroxide sodium permits the formation
of longer chains and thus enhances particle stability. Maximum molar masses of 1200 g/mol are reached
even in the latter polymerization conditions, a critical chain length for which oligomers lose their surface
activity and stop propagating.