POLYMERIC SURFACTANTS IN LATEX TECHNOLOGY - POLYSTYRENE-POLY(ETHYLENE OXIDE) BLOCK-COPOLYMERS AS STABILIZERS IN EMULSION POLYMERIZATION

Polystyrene-poly(ethylene oxide) PS-PEO di- and triblock copolymers have been used as stabilizers in the emulsion polymerization of styrene and styrenebutylacrylate for the preparation of ''hairy latexes''. The polymerization kinetics and the efficiency of these polymeric surfactants were correlated with the molecular characteristics of the block copolymer. It was shown that the efficiency decreased with increasing molecular weight and PS content of the block copolymer. The PEO fringe, with a thickness of 4-25 nm, on the latex particle surface could be characterized and it was shown by differential scanning calorimetry (DSC) that water is structured in that PEO layer. Film formation with ''hairy latexes'' was also examined both by DSC and thermomechanical analysis. The properties and application possibilities, such as in controlled latex flocculation, have been reviewed.