SYNTHESIS AND CHARACTERIZATION OF A SHORT-HAIRED POLY(ETHYLENE OXIDE)-GRAFTED POLYSTYRENE LATEX

A method is discussed for the preparation of charge-stabilized polysty rene latex particles carrying terminally grafted short poly(ethylene o xide) (PEO) chains. The latices have relatively large particles (size, 480 nm), a surface charge, and possess on the surface a methoxy PEO/m ethacrylate molecule (containing 8 segments of EO). The surface proper ties of this latex are compared with those of a similar latex but with out the PEO surface group. The presence of the PEO moiety on the parti cle surface could be established by determination of the colloidal sta bility against salt, complexation with molybdatophosphoric acid, prote in adsorption and proton NMR. From the molybdatophosphoric acid and pr oton NMR results it follows that the average surface coverage of PEO c hain is roughly 1 molecule per square nanometre.