Synthesis And Property Study Of Waterborne Polyurethane Emulsion Modified With Perfluoropolyether Acrylate

Nowadays, waterborne polyurethane modified with fluorinated acrylates have shownsome special properties and a lot of research effort has been paid in this area. In this paper, thepolyurethane-acrylate was used as a fluorinated monomer to modify waterborne polyurethane, theobtained emulsions applied on cotton fabric to provide water and oil repellent properties.A series of vinyl-terminated waterborne polyurethane (WPUA) were prepared byisophorone diisocyanate (IPDI), poly(tetramethylene oxide glycol)(PTMG),1,4-butanediol(BDO), dimethylol propionic acid (DMPA),2-hydroxyethyl methacrylate (HEMA). A series ofnovel waterborne fluorinated polyurethane-acrylate hybrid emulsions were synthesized via freeradical emulsion polymerization by using vinyl-terminated waterborne polyurethane (WPUA) asseed emulsion with perfluoropolyether acrylate (FA), methyl methacrylate (MMA), N-butylacrylate (BA) as monomers, with KPS as a polymerization initiator. Nano particle size analysisshowed that WFPUA composite emulsion particles distributed between50-100nm, and had goodstability. Thermal gravimetric analysis (TG) showed the T50of WPUA as345.5°C, with theaddition of fluorinated acrylate, the T50of WFPUA40reached375.8°C, indicating that thethermal stability of polyurethane had been improved to some extent. The WFPUA compositeemulsions had core-shell structure by Transmission electron microscopy (TEM). The waterabsorption of the WFPUA films were reduced as the amount of fluorine-containing increased,decreasing from18.9%of WPUA to2.6%of WFPUA40. Besides, the contact angles of waterfor the surface of films were increased from72°of WFPUA10to109°of WFPUA40, indicatingthat the surface energy of WFPUA polymers were decreased and the water resistance of the filmswere improved.These copolymer emulsions were applied on cotton fabrics by pad-cure-dry finishingprocess. The surface morphology, composition and properties of cotton fabrics finished withcomposite emulsions were analyzed and discussed by scanning electron microscopy (SEM), X-rayphotoelectron spectroscopy (XPS) and contact angle measurement (CA), respectively. The resultsshowed that the surface of the finished cotton fabrics covered with a layer of smooth polymer film,and the fluorine content of cotton fabric surface reached the highest level when treated with WFPUA40composite emulsion. Besides, the surface of cotton fabrics treated with the hybridemulsion had good surface property with142oof contact angle for water and124°for paraffin oil,demonstrating that the treated cotton fabrics had good water repellent properties and certain oilrepellent properties.