Abstract:

Fluorinated emulsifier-free polyacrylate emulsion with a core-shell structure was synthesized via the pre-emulsified seed emulsion polymerization,with methyl methacrylate（MMA）,butyl acrylate（BA） and hexafluorobutyl methacrylate（HFMA） as the main monomers,and with ammonium allyloxtmethylate nonylphenol ethoxylates sulfate（DNS-86） as the polymerizable emulsifier.Then,the influences of the dosages of DNS-86 and HFMA on the electrolyte stability of the emulsifier-free emulsion and on the water resistance of the film were discussed. Moreover, the emulsion and the film were characterized by means of FT-IR, TEM, DSC, contact angle method and TG. The results show that, as compared with the traditional complex emulsifier OP-10/SDS, polymerizable emulsifier DNS-86 may result in stronger electrolyte stability and water resistance in the polymerization with 2.2% DNS-86 and 8% HFMA, that HFMA effectively participates the emulsion copolymerization, that there exists a clear coreshell structure in emulsion particles, that the emulsifier-free emulsion film is of two glass transition temperatures, namely 261.11 and 300.48 K, which respectively correspond to the core-phase and the shell-phase copolymers, and that, at a HFMA dosage of 8%, the water contact angle of the film-air interface reaches 94.1 ° and the decomposition temperature of the emulsifier-free emulsion film is 48 K higher than that of the traditional polyacrylate emulsion film, showing a greatly-improved hydrophobie property and thermal stability of the film.

Key words: polymerizable emulsifier, emulsion polymerization, fluorinated polyarcylate, core-shell structure, emulsifier-free emulsion