Study On The Synthesis And Application Of Fluorine-containing Acrylate Co-polymer Emulsion With Core-shell Structure

Fluorinated acrylate copolymer emulsion is one of the most importantfluoropolymers. It was widely applied in the fields of textile finishing, leather andpaper coatings, building anti-fouling materials, and so on because of its very lowsurface energy. Now, the key synthesis technology of fuluorinated acrylate copolymeremulsion was mastered firmly by abroad, and the relavent products had been launchedin the market. In this area, however, there still exist some gaps between the domesticand abroad researches on the preparing of the fluorine-containing acrylate co-polymeremulsion. The key problems are as follows: low effective utilization of fluoridemonomer, higher price, large-scale product in domestic.A novel core-shell structure fluorine-containing acrylic copolymer emulsion wasprepared successfully by pre-emulsion and semi-continuous in the presence ofβ-cyclodextrin(β-CD). The main monomers were methyl methylacrylate(MMA) andbutylacrylate(BA) and the dodecafluoroheptyl methylacrylate(DFHMA) was thefluorine-containing monomer.The polymerization process was studied, in which the effects of many factors onthe monomer conversation, particle size, and size distribution and stability offluorine-containing acrylic copolymer emulsion were stressed. The results showedthat theβ-CD had little influence on final monomer conversation but couldobviously promote the polymerization reaction rate. Higher monomer conversationwas obtained when amount of initiator APS was 0.6wt%～1wt%, polymerizationtemperature was 80℃. Conversation gradually decreased with the increasing of thecontent of fluorinated monomers. Particle size distribution tests showed that theobtained fluorine-containing acrylic copolymer emulsion had smaller particle sizewhich was in the nanometer and had good monodispersity. New particles were notfound in the shell polymerization, which proved that the final product was acopolymer.The structure and surface properties of fluorine-containing acrylic copolymerlatex film were characterized by means of the infrared spectrometry(FTIR),transmission electron microscopy(TEM), X-ray photoelectron spectroscopy(XPS),contact angle testing. We found that the fluorinated monomer was effectivelypolymerized and the copolymer emulsion had obvious core-shell structure, goodmonodispersity and stability. Latex film displayed good surface properties.Finally, the water and oil-repellent finishing technology with fluorine-containingcopolymer emulsion treating cotton fabrics was also discussed. Meanwhile, the finishing effect was also compared with that obtained by the treating of thefluorine-containing finishing agent in the market. The water-repellent level of treatedcotton fabrics was 7 and oil-repellent level was 1, which indicated that the fabirics hadgood resistance to water performance by the finishing of our latex. Compared with theproducts in the market, however, the homemade fluorine-containing acrylatecopolymer emulsion needs to be further improved.