Stable miniemulsions of styrene or yl, methacrylate (MMA) were prepared in
the presence of hexadecane and a styrenic polymerisable surfactant, the vin
ylbenzylsulfosuccinic acid sodium salt (VBSS). They were polymerised to hig
h conversion, using potassium persulfate (KPS) or 2,2'-azoisobutyronitrile
(AIBN) with no significant change in the particle size during reaction. The
stability of the latexes was excellent when KPS was used, and the reasons
for this are discussed. The size of the particles was further increased by
using these latexes as a seed, and feeding a continuous stream of monomer i
n the presence of another polymerisable nonionic surfactant.