Study On Self-organized Gradient Materials Of Fluorirated Acrylate Polymers Prepared By Emulsion Method

Gradient polymer materials through self-organization have attracted increasing attention of many investigators recently. When one component in blends has special functional groups, this component could self-organize to the surface of blend films during film-formation process or annealing process, and accordingly, a film surface with special properties is obtained. Fiuorinated acrylate polymers have much lower surface free energy than non-fluorine acrylate polymers, so self-organization will happen during the film-formation of their latex blends under effects of surface free energy. Finally, a fiuorinated acrylate polymer material with gradient film structure is obtained. In this gradient material, one surface side of the blend film exhibits special surface properties, such as antifouling property, self-cleaning property, water-resistance and oil-resistance, whereas, the other surface side shows good adhesion to matrixes.The creative achievements of this thesis are as follows. (1) It has been systemically studied the film-formation conditions which promise fiuorinated acrylate core-shell latex to self-organize gradient film structures, and it has been detailedly discussed the position effects of fiuorinated components in core-shell particles on the properties of the latices. (2) It has been comprehensively discussed that blend components, film-formation matrixes and heat-treatment conditions significantly influenced gradient structure formation of latex blends of poly(trifluoroethyl methacrylate) latex and poly(BA-co-MMA). (3) Emulsifier-free latex of poly(trifluoroethyl methacrylate) has been synthesized for first time by using surfmer and acetone. (4) It has been clarified for first time the effects of annealing process and film-formation matrixes on the gradient structure formation of the emulsifier-free latex blends of poly(trifluoroethyl methacrylate) and PBA. (5) Emulsifier-free latices of fluorinated acrylate copolymers has been successfully prepared by adopting ultrasonic emulsification, and the properties and film structures have been studied in detail.The main research contents and conclusions are divided into the following parts. Fiuorinated polyacrylate latices with core-shell structure were prepared by using themixed emulsifier system composed of a reactive emulsifier and a little anionic emulsifier. The latex films containing fluorine showed low surface energies and high water contact angles. The position of fluorinated components in core-shell structure had great effects on the surface and thermal properties of the latex films. Compared to the core-shell structure with the fluorinated core, the core-shell structure with the fluorinated shell was more effective to modify the properties of the latex films. Moreover, the increase of FMA amount in shell decreased the film surface energy and enhanced the film thermal stability. The surface analysis from XPS indicated that the fluorinated component preferentially self-organized at the film-air interface. Depth profiling of the latex film proved that the gradient concentration of fluorine existed in the structure of the latex film from the film-air interface to the film-glass interface.The latex blends of poly(trifluoroethyl methacrylate) (PF3MA) and PBA-MMA were prepared. It was discussed that blend components, film-formation matrixes and heat-treatment conditions significantly influenced gradient structure formation of latex blends. With increasing PF3MA amount in the blend, the surface free energy in film-air interface of blend films decreased. When the glass was film-formation matrix and the weight ration of (PF3MA) to PBA-MMA was 3:5, the surface free energy in film-air interface of blend films decreased with enhancing heat-treatment time, and the blend film could self-organize to form a gradient structure after heat-treating 5.5h at 105°C. The kind of film-formation matrix could change the self-organization and movement of polymer components and emulsifier in latex blend during heat-treatment.Emulsifier-free latex of PF3MA has been synthesized by the exist of surfmer (DVP) and acetone. The polymerization kinetics and mechanism of particle nucleation of PF3MA emulsifier-free latex were discussed. Increasing APS and acetone amount or enhancing reaction temperature could improve polymerization rates. When DVP amount was 3wt%, the polymerization exhibited the characters of normal emulsion and emulsifier-free emulsion polymerization. The average size of obtained latex particles was 263.7nm, and particles showed monodispersion. Tgof synthesized PF3MA was 81°C. Synthesized PF3MA had slight crystalline property and good heat-resistance.The emulsifier-free latex blends of poly(trifluoroethyl methacrylate) (PF3MA)and PBA were prepared. It was clarified the effects of annealing process and film-formation matrixes on the gradient structure formation of the emulsifier-free latex blends. When glass was film-formation matrix and the weight ration of (PF3MA) to PBA was 5:3, the surface free energy in film-air interface of blend films decreased with annealing time, and the blend film could self-organize to form a gradient structure after annealing 2h at 90°C. The kind of film-formation matrix could change the self-organization and movement of polymer components and emulsifier in latex blend during annealing. The copolymer of F3MA and BA could modify the compatibility of PF3MA/PBA emulsifier-free latex blend.Emulsifier-free latices of fluorinated acrylate copolymers were prepared by the semicontinuous polymerization method. The optimal polymerization condition was 0.7% APS, 0.95% COPS-1, and 1.0% AA. The suitable ultrasonic emulsification time was 15 min. The results of FT-IR and DSC proved that the random fluorinated acrylate copolymer was obtained and its Tg was 54°C. After perfluoroalkyl groups were introduced into polymer chains, the wetting-resistance, the water-resistance and the thermal stability of the latex films were evidently enhanced. The gradient structure film was not obtained due to random copolymer chains.In this thesis, the relationship between film-formation conditions and the gradient film structure of fluorinated acrylates core-shell latices or latex blends through self-organization has been clarified, and the polymerization method of fluorinated acrylates emulsifier-free latices has been developed. The results of the researches motioned above not only provide the scientific foundation for the preparation of self-organization gradient material of fluorinated acrylate latex, but also the new way to the exploitation and utilization of fluorinated polyacrylates. The progress of blending in latex system belongs to green technology. It is worth noting that researchers and ultilizing of renewable resources are compliant with the national objective and sustainable development.