Study on properties of organic fluorine modified waterborne polyurethane

A fluorinated waterborne polyurethane was prepared by modification of water-based polyurethane using 1H,1H,8H,8H-dodecafluoro-1,8-octanediol(F12), and then characterized by infrared spectroscopy and scanning electron microscopy. The water absorption rates, water contact angles,and mechanical properties of the fluorinated water-based polyurethane coatings prepared with different contents of F12 were studied. The results showed that the water contact angle,adhesion strength, and hardness of the prepared fluorinated water-based polyurethane coating are increased gradually with increasing content of F12 while the water absorption is decreased, and the tensile strength and elongation at break are increased initially and then decreased. When the content of F12 is 0.3%-0.4%, the comprehensive performance of the coating obtained is the optimal: adhesion strength 1 grade, pencil hardness H-2H, flexibility 3-5 mm, tensile strength 16.32-18.64 MPa, elongation at break 397.65%-301.65%, water absorption rate 7.1%-6.7%, and water contact angle 67°-72°. The F12-fluorinated water-based polyurethane has low surface energy as well as good tensile strength and water resistance, being able to be used for fabrics and as a marine antifouling coating material.