Preparation and properties of waterborne polyurethane modified by aminoethylaminopropyl polydimethylsiloxane for fluorine-free water repellents

Abstract Waterborne polyurethane (WPU) prepolymers were firstly synthesized by toluene diisocynate (TDI), trimethylolpropane (TMP), polydimethylsiloxane (PDMS), N-methyldiethanolamine (N-MDEA) and glycerin monostearate (GMS). Then the prepolymers were chain-extended by aminoethylaminopropyl polydimethylsiloxane (AEAPS) to obtain fluorine-free water repellents. In this paper, the structure of AEAPS-modified waterborne polyurethane (AEWPU) was characterized, and the influence of different AEAPS contents on stability, particle size and viscosity of AEWPU, the waterproof performance, surface energy, contact-angle hysteresis and morphology of the AEWPU films. The application properties of the fabrics finished by AEWPU, the elements distribution of the film and the finished fabric were also discussed. The optimum AEAPS content of the water repellent was 20 wt%, then the highest score of 90+ was obtained.