Synthesis And Application Of Cationic Polymerizable Surfactants

Polymerizable surfactants not only play as an emulsifier in emulsion polymerization,but also take part in polymerization.They adsorb in chemical action to the surface of latex particles and to be one part of the polymer.Therefore polymerizable surfactants can improve the stability of the lattices versus electrolyte and freeze/thaw,as well as the water sensitivity of the film formed.Cationic surfactants have been a widely applications in antistatic agents, bactericide and other special areas,but their performance of emulsification and dispersion are worse than anionic surfactants,while non-ionic groups being introduced in emulsion polymerization may improve their performance.A series of polymerization surfactants(surfmers)were synthesized,whose structures combined the characteristics of polyoxyethylene as nonionic group and quaternary ammonium as cationic group.The structures of the product were confirmed by MS,and the content of cationic-activity matter was determined by two-phase titration.The surfmers were then used with constant addition profiles in semicontinuous polymerization of vinyl acetate-butyl acrylate-Veova 10-hexafluorobutyl methacrylate.And the polydispersity indexes (PDI)were lower than 0.1.The particle size,amount of coagulum,and stability against electrolyte and freeze/thaw were evaluated.As a reference,an unreactive surfactant cetyl trimethyl ammonium bromide(CTAB)was also used for the polymerization.Compared to CTAB,the surfmers behaved much better.Not only stabilities to electrolyte and water resistance were improved,but also freeze/thaw stability got a superior performance.A series of surfrners(F)were also synthesized.[2-(N,N-diethylamino)ethyl]long-chain ethyl fumarate quaternary ammonium salt,cationic fumaric surfmers,were prepared with maleic anhydride,then reacting with PCl₃.The chemical structures of the surfmers were confirmed by MS and ¹H NMR.The surfmers were then used with constant addition profiles in semicontinuous polymerization of vinyl acetate-butyl acrylate-Veovea 10-hexafluorobutyl methacrylate.Polydispersity indexes(PDI)of latexes were all lower than the limit(0.1)of monodispersity.The results of bonding rate for series polymerizable surfactants were all 100%.Compared to CTAB,the surfmers behaved better in either the stability to electrolytes or storage stability of the lattices.When the films,which were prepared from the CTAB and surfmers,were immersed into water after 28 days,water absorption of the film made with CTAB(104.50%)was 2.22 times higher than that with F2(47.06%),2.38 times than F3(44.24%),6.34 times than F4(16.48%),3.94 times than F5(26.50%)and 3.16 times higher than that with F6(33.12%).So,polymerizable surfactant can greatly improve the water resistance of films.The Minimal Inhibitory Concentration(MIC)of escherichia coli and the antibacterial activities of the films were tested.The results manifested F series emulsifiers were good bactericide.So,it will be helpful to develop new antibacterial coating.