A variety of non-ionic reactive surfactants have been prepared from block copolymers precursors. These precursors are formed from a commercially available polyethylene glycol monoethylether as the hydrophilic sequence of the surfactant; this product is used as initiator of living polymerization of butylene oxide. Finally the reactive surfactants are obtained after proper functionalization of the precursors. The reactive surfactants are an inisurf with an asymmetric azo compound, a transurf with a thiol group, and a few surfmers with acrylic, methacrylic, styrenic and a-methylstyrenic reactive groups. These compounds have been engaged in styrene emulsion or dispersion polymerization. Several of them are useful to prepare stable latexes.