Effect of fluorine atom positions on the properties of waterborne polyurethanes

Series of waterborne polyurethane were synthesized with isophorone diisocyanate (IPDI) and polycaprolactone diol (PCL) in this paper. Two different fluorine monomers were introduced into waterborne polyurethane (WPU) systems, respectively. The two-dimensional fluorinated molecular chains and the three-dimensional fluorinated cross-linking networks were severally established in WPU systems. Then the effect of fluorine atoms' position on the performance of the fluorinated waterborne polyurethane (FWPU) films was investigated. The test results showed that in two-dimensional molecular chains, the film with fluorine-containing side chains had better performance. Moreover, when fluorinated side chains were introduced after the formation of the crosslinked network, waterborne polyurethane had better properties. This film possessed greater thermal stability and its glass transition temperature was −60.86 °C. The WPU-D-B had a better water contact angle of 104.70° as well as better mechanical qualities with a tensile strength of 37.67 MPa, which had better water resistance, mechanical properties and thermal stability.