Emulsion polymerization of transparent core-shell latices with a polydivinylbenzene styrene and vinyl acetate

There is today a big need for polymeric material with well-defined nanostructures. Especially the field of transparent biomaterials is an intensively investigated area. The question if seeded emulsion polymerization of vinyl acetate (VAc) onto polydivinylbenzene (PDVB) seed latices is an appropriate way to obtain transparent latices with a core-shell structure is especially interesting because this material is very promising due to its unique properties as biocompatible optical material. It is shown that vinyl groups on the surface of the PDVB inhibited the conversion of seeded VAc polymerization due to unfavorable reactivity ratios of VAc and styrene (Sty) groups. The results show that covering the vinyl groups of the PDVB seed latex with a layer of polystyrene (PSty) is an option to overcome the inhibition and still obtain transparent latices. The polymerization of VAc onto double-layer PDVB/PSty seed latices could be run up to 100% conversion. Transmission electron microscopy (TEM) measurements in combination with RuO4 and uranyl acetate staining are a reliable tool for investigating the core-shell morphology of the extremely small PDVB/PSty/PVAc multilayer latices obtained