Distribution Of Surfactants In Fluorinated Polyacrylate Latex Films And Study Of Film-formation Of Latex Blends

Currently, gradient polymer materials have attracted more attention by latex blend method, due to economical, environmental and excellent surface properties. The presence and enrichment of emulsifiers in latex film influence evidently for its surface properties. Therefore, it has been systemically studied the distribution of free and adsorbed surfactants in the fluorinated copolymer latex film. Furthermore, it has been comprehensively discussed the distribution of various emulsifiers in latex film. Finally, the effects of annealing process on self-organization film-formation have been studied in detail.Firstly, Fluorinated polyacrylate latexes were prepared by emulsion copolymeri-zation of hexafluorobutyl methacrylate (F6MBA) and hexafluorobutyl acrylate (F6BA) in the presence of AES, SDS, SDS/OP-10(2/1,1/1,1/2), DNS-86 and CTAB/AEO-9 (1/1), CTAB as surfactants, respectively. The distribution of the surfactants in the fluorinated polyacrylate latex films was researched by surface free energy analysis, differential scanning calorimeter (DSC), atomic force microscope (AFM) and scan-ning electron microscopy energy dispersive analysis (SEM-EDX). It was found that the concentration of non-reactive surfactants enriched at the film-air interface. Sur-factants enriched at interface, including free surfactants and adsorbed surfactants. Surfactant migrated to the interior of latex film during annealing process. Further-more, the variation of surface free energy is different for different latex films that prepared with cationic emulsifier and anionic emulsifier, respectively. Finally the en-richment disappeared after annealing treatment. Whereas, the reactive surfactants dis-tributed uniformly in the latex films.Secondly, the resultant PF6MBA-co-F6BA copolymer emulsions with different kinds of surfactants respectively mixed with fluorinated-free acrylate copolymer (2/1 and 1/2, w/w) with the surfactant, Tween-20. The eight blend latexes filmed at 30℃and 45℃and annealed at 110℃for deliberated time. The surface free energy of the film-air interface first increased and then unchanged in the system (PF6MBA-co-F6BA Tg<45℃, PMMA-co-BA Tg>45℃). However, in the other system (PF6MBA-co-F6BA Tg<30℃, PMMA-co-BA Tg<30℃), the surface free energy of the film-air interface first decreased and then unchanged. The content of fluorine in film-thickness direction were analyzed by SEM-EDX. It was found that the fluorine content increased from the film-glass interface to film-air interface smoothly in the blend film, probably because fluorine move more easily in the first system than the second system in film-formation process, resulting in the gradient film structure is more obvious in the process of annealing...