Synthesis and Surface Properties of Waterborne Polyurethane Modified by Polysiloxane

A series of polysiloxane modified waterborne polyurethanes(WPUs) were prepared by using polyoxypropylene glycol (PPG) and bihydroxy hydrophilic polysiloxane polyol(UC3667) as soft segments, isophoronediisocyanate (IPDI), 1,4-butanediol (BDO), dimethylolpropionic acid (DMPA) and ethylenediamine (EDA) as hardsegments. The particle size and membrane structure of aqueous waterborne polyurethane emulsions were characterized by DLS and FTIR. The properties of waterborne polyurethane films were characterized by thermogravimetric analysis, tensile test, contact angle test and X-ray photoelectron spectroscopy. The results showed that when the content of polysiloxane increased, the tensile strength of waterborne polyurethane films firstly increased and then decreased.Moreover, the introduction of polysiloxane improved the thermal stability,elongation at break, contact angle of waterborne polyurethane films and reduced surface energy. When the mass fraction of polysiloxane was 5.0%, polysiloxane migration on the surface of the film reached saturation, and the surface energy was 27.27 mJ/m2. © 2019, Editorial Office of FINE CHEMICALS. All right reserved.