Preparation And Study On Liquid Repellent Properties Of Novel Fluorinated Polyacrylates

With the development of people's living standard,the functionality of textiles become the focus of interest in the market.Consequently,fluorine-containing polymers have been widely studied in recent years especially in the field of textile industry to impart fabrics good water and oil resistance.Varieties of water-and oil-repellent fluorinated polymers are available as finishing of fibrous substrates in the market.Fluorocarbons especially those with long perfluoroalkyl chains (C_nF_2n+1,n≥8) are widely used as the most important class of water and oil repellent finishing agents for textiles due to therir optimum performance in lowering the surface free energy and improving both hydrophobicity and oleophobicity.In recent years,the fluorocarbons containing long perfluoroalkyl chains are facing the problems such as the persistence,bioaccumulation,and toxicity in the environment.The use of perfluorooctyl contained surfactants such as PFOS and PFOA have been restricted in the international community.Sooner or later,fluorocarbons with long perfluoroalkyl chains will face the same problems.So it is important to find the alternatives to replace the present long perfluoroalkyl-contained fluorocarbons.Starting from commercially available(methyl)acryloyl chloride,4-hydroxybenzoic acid, 2-hydroxyethyl acrylate,Isophorone diisocyanate(IPDI) and lH,lH,2H,2H-perfluorooctanol, fluorinated acrylate monomers 1,2 and 3 containing functional groups of benzene ring and -NHCOO-.At the same time,acrylic acid and lH,lH,2H,2H-perfluorooctanol were used to synthesize fluorinated acrylate 4 in comparison with 1,2 and 3.The above obtained fluorinated acrylate monomers were copolymerized with other functional acrylate monomers by emulsion polymerizations to provide fluorinated co-polymers PFA1,PFA2,PFA3,PFA4 respectively.The influences of polymerization conditions,such as concentration of emulsifying agents and initiator, time of reaction on stability of polymerization and conversion were studied,as a result all the polymerization conditions were optimized.The particle size distribution of the emulsions was measured by MarIvern2000 and the co-polymers were characterized by FT-IR.The surface properties of these co-polymers were studied by applied on the cotton fabrics. The change of external geometry morphology of the fabric before- or after-treatment was shown by SEM which explained the water and oil repellence properties of textile after-treatment.The fabrics treated with PFA1,PFA2 and PFA4 all showed good water and oil repellency with contact angle of 140°for water and of 110°for n-dodecane.This result was comparable to the existing fluorinated polyacrylate with long perfluoroalkyl chain.However,PFA3 showed lower water repellent property and no obvious oil repellent property.