The core-shell structured aqueous dispersions of the siloxane-grafted polyurethane copolymers with high transparency

We have synthesized the siloxane-grafted polyurethane copolymers aqueous dispersions by semi-continuous emulsion polymerization. The mono-methacryloxypropyl terminated polydimethylsiloxane was used to react with the acrylate-terminated waterborne polyurethane, which served as seed emulsions. It is obtained that the as-synthesized copolymer dispersions are stable and have small particle sizes ranging from 77 nm to 120 nm, and they possess core-shell structures. Moreover, the results show that the prepared films exhibit high transparency and hydrophobic surface. Moreover, the enrichment of siloxane and the heterogeneous structure on the film surface was studied. The results of Raman spectra disclose that the intensities of siloxane on the surface change over time during the film formation. These results are correlated to the pressure difference of droplets and low surface tension of siloxane segments. The as-synthesized dispersions promise to be applied in the displayer coatings.