Preparation And Characterization Of Fluorinated Acrylate Copolymer Latex

The polymers of fluorinated acrylate have the extremely low surface free energy because of unique long chain fluorinated alkyl structure introduced, thus fluorinated acrylate polymers have been used to a progressively greater extent in surface coatings, such as water and oil repellency for textile, paper and leather. In recent years, the emulsion polymerization technology of fluorinated acrylate taking the water as a environmental secure medium has attracted the increasing attention of many investigators.Actyflon-G04(C₁₁H₈O₂F₁₂), BA and MMA were used as basic monomers, SDS and OP-10 as emulsifying agents, KPS as initiator in this study. Copolymers of fluorinated acrylate and free-fluorinated acrylate with different structures were synthesized by different methods.Tow-stage emulsion polymerization was applied in this study. At first stage, the seed emulsion polymers were obtained, and for the second stage polymerization, we studied the influence of feeding method on structure of latex particles. The size distribution and morphology of particle were measured by Malvern2000 and transmission electron microscopy(TEM). The compositions of polymer were analyzed by thermogravimetric analysis(TGA) and its solubility in THE The surface compositions and properties of the latex films were characterized by ATR-FTIR and contact angle method. The results showed that the method of batch can not obtain ideal core-shell particles. Core-shell particles with fluoropolymer rich in shell were synthesized by controlling the short time of swelling and the low conversion of seed emulsion. We also prepared interpenetrating polymer networks(IPN) with long time of swelling. The contact angle of latex film to water and octanol and the surface composition showed that core-shell particles can make fluoropolymer rich in surface.The particles synthesized by semi-batch method dropping FA pre-emulsion have complete core-shell structure and good size distribution. The influences of polymerization conditions, such as methods of feeding monomer, concentration ofemulsifying agents and initiator, time of feeding on stability of polymerization, conversion and stucture of copolymer were studied. This method improved the stabilities of polymerization and storage. Compared with that of other morphological polymer, the surface free energy of core-shell latex film was minimal, and do not show obvious advantage if we increased w(FA) in the core-shell particles by over 30%.