Emulsion copolymerization of hydrophobic and hydrophilic monomers: An experimental study with styrene and 2-hydroxyethyl methacrylate

Abstract

Ab initio emulsion copolymerization of styrene with 2-hydroxyethyl methacrylate (HEMA) at weight ratios of the hydrophilic monomer of 1 and greater was investigated at various temperatures in dependence on the concentration of sodium dodecylsulfate (SDS) and potassium peroxodisulfate as emulsifier and initiator, respectively. Both the course of the polymerization and the latex properties are strongly influenced by the hydrophilic monomer. For instance, transparent or highly translucent latexes are obtained resembling the appearance of microemulsion latexes with polymer contents as high as 10 weight-% but at much lower surfactant concentration. Moreover, polymerization rate, average particle size, and particle morphology depend on the surfactant and initiator concentration, monomer feed composition, and polymerization temperature.