Structure and application performance of polyurethane modified by fluorinated polysiloxane

In order to study the relationship between the structure and application performance of water-borne polyurethane modified by fluorinated polysiloxane(WFSPU), the phase separation characteristic, free volume hole size and surface elements of WFSPU film were investigated by dynamic mechanical analyzer, positron annihilating life spectrometer and X-ray photoelectron spectroscopy instrument respectively. The application performance of coated fabric including cohesive strength, moisture permeability, water repellency and elasticity were tested by using fabric strength tester, water resistance tester for fabric, water vapor permeability tester, contact angle meter and crease recovery angle tester. The results show that, compared with unmodified polyurethane, the microphase separation degree of modified polyurethane improved, size and percentage of free volume hole of polyurethane film increased, and some F, Si element migrated to film surface; as the AFS content increasing, The cohesive force between coating and fabric increased gradually, the moisture breathability of coated fabric increased first and then decreased, the hydrostatic pressure decreased gradually, the water repellency of coated fabric increased gradually, and the elasticity increased first and then decreased. In all, the performance of WFSPU was best when the mass fraction of AFS was 6%.