Preparation of fluoropolymer with gem-bis-fluoroalkylated side-chain and its application on cotton fabric finishing

In this study, three types of fluorinated polyacrylates (PBFB, PBFS, and PMFA) were synthesized by 4-gembis(2,2,3,3,4,4,5,5,5-nonafluoropentyl)-1-butene, 4-gem-bis(2,2,3,3,4,4,5,5,5-nonafluoropentyl)-methine-1-styrene, and 3,3,4,4,5,5,6,6,6nonafluorohexyl acrylate, respectively, as monomers via emulsion polymerization. Particle size, particle size distribution, and zeta potential were tested to assess the emulsion stability. Afterwards, the latexes were coated onto fabrics to obtain gem-bis(fluoroalkyl)-cotton. The surface properties of the treated cotton fabrics were analyzed by X-ray photoelectron spectroscopy and water contact angle. It was found that, when controlling the fluorine content level to be similar, the water contact angles of gem-bis(fluoroalkyl)-cottons were 127 degrees +/- 0.5 degrees and 134.9 degrees +/- 0.7 degrees, respectively, which were both higher than that of mono-fluoroalkyl-cotton (PMFA-cotton of 125.2 degrees +/- 0.2 degrees). This showed that gem-bis-fluoroalkyl groups could provide better hydrophobic performance than the mono-fluoroalkyl group, especially when the rigid benzene was used as a side-chain bridged group.