Preparation and properties of UV-curable waterborne silicon-containing polyurethane acrylate emulsion

The non-toxic and environmental protection characteristics of water-based coating make it has a good development prospect, but its poor water resistance and stability have attracted widespread attention. A type siliconcontaining polyurethane acrylate core-shell structure emulsion was prepared by using in-situ self-emulsification, and it was applied to fabric-based substrates to study the influence of the different distribution of groups on the surface of the coating on the interfacial properties of the fabric-based coating. The silicon-containing polyurethane acrylate was synthesized by grafting unsaturated double bond with silane coupling agent which was characterized by FTIR and 1H NMR. The stability of the emulsion was tested by dynamic light scattering technique. The distribution of latex particles and the core-shell structure were observed by transmission electron microscopy (TEM). After the introduction of vinylsiloxane, the particle size of polyurethane acrylate emulsion decreased from 180.3 nm to 111.7 nm, and the emulsion samples could be stored for 6 months stably. The surface properties and morphology of the cured polyurethane acrylate film samples were evaluated by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The thermal stability of cured film was analyzed by thermogravimetry (TG). In addition, emulsion samples with different silicone contents were coated on different fabric-based substrates (cotton fiber, PET and PP), and the fabric based coatings were cured quickly by utilizing the characteristics of fast UV curing and low energy consumption. The low surface energy organosiloxane was easier to migrate to the surface of the material, which increased the surface tension of the fabric based coatings. The water contact angles of the coatings interface were greater than 100 degrees, showed good hydrophobic performance. In addition, the emulsion was dipped into the fabric-based substrate and it was found that the content of polar groups (-COO-) on the surface of the fabric-based coatings gradually increases along with increase of the concentration of the emulsion and the number of dips, and the organosiloxane originally on the surface of the coating was coated on the inner layer, made the hydrophobic performance of the coating decreased and when the emulsion concentration increased to 0.5 g/mL or the dip coating reached 5 layers, the interfacial performance of the coating changed from hydrophobic to hydrophilic. And the fabric based coatings with adjustable interfacial properties were obtained.