Effect of polymerizable emulsifier and fluorine monomer on properties of self-crosslinking fluorinated polyacrylate soap-free latexes

摘要

We used a polymerizable emulsifier, ammonium allyloxtmethylate nonylphenol ethoxylates sulfate (DNS-86), to synthesize self-crosslinking fluorinated polyacrylate soap-free latices (FMBN) with a core-shell structure by a semicontinuous seeded emulsion polymerization method from dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and N-methylolacrylamide (NMA) as self-crosslinking functional monomer. Then we examined the effects of DNS-86 and DFMA on stability, average particle size and hydrophobicity of the FMBN latices or their films in detail. While dosage of the DNS-86 and the DFMA were employed as 3 wt% (on the basis of the total-monomers weight) and 8 g in our recipe, the latex and its film could be acquired with higher stability and a smaller particle size and polydispersity index, as well as favorable hydrophobicity. FTIR confirmed the structure of the FMBN. The emulsion particles' core-shell structure was observed by transmission electron microscopy. Thermal stability of the copolymer was greatly improved with the increasing of the DFMA level. X-ray photoelectron spectroscopy analysis indicated that the fluoroalkyl groups tended to enrich at the film-air interface. Meanwhile, hydrophobicity of the self-crosslinking soap-free latex film showed some improvement compared to the general one and the non-crosslinked one.