Fluorinated polyacrylate emulsifier-free emulsion mediated by poly(acrylic acid)-b-poly(hexafluorobutyl acrylate) trithiocarbonate via ab initio RAFT emulsion polymerization

摘要

Fluorinated polyacrylate emulsifier-free emulsion was synthesized via ab initio RAFT emulsion polymerization mediated by poly(acrylic acid)-b-poly(hexaflurobutyl acrylate) (PAA-b-PHFBA) trithiocarbonate macro-RAFT agent. The influence of the amount of PAA-b-PHFBA and hexafluorobutyl acrylate (HFBA) on emulsion polymerization and film properties was investigated. The monomer conversion increased, and latex particle size decreased as the amount of PAA-b-PHFBA increased from 2 wt% to 4 wt%, then the monomer conversion decreased slightly and particle size increased slightly. The latex particles presented spherical-like particles with diameters of 40-120 nm characterized by TEM. The results of contact angle and XPS revealed that the fluorine preferentially concentrated at the film surface during film formation process. The film-air interface of film was more hydrophobic than the film-glass interface. The water contact angle of the film increased initially as the amount of HFBA increased, then decreased slightly. The thermal stability increased with increasing the amount of HFBA. The film formed from the fluorinated polyacrylate latex with PAA-b-PHFBA as stabilizer showed higher thermal stability and hydrophobicity than that with reactive emulsifier.