The Addition Of Epoxy Soybean Oil Improves The Water Resistance Of Waterborne Polyurethane Film
The addition of epoxy soybean oil improves the water resistance of the waterborne polyurethane film. For this knowledge, we should understand that the introduction of hydrophilic groups in the preparation of anionic waterborne polyurethane reduces the water resistance of the polyurethane film. , Through the internal cross-linking of epoxy soybean oil, the polyurethane molecular chain can form a partial cross-linked structure, and the long-chain hydrophobic segment can be introduced to improve its water resistance and solvent resistance. Each epoxy soybean oil molecule has ~4 epoxy groups, which can react with —NCO groups to form a partially cross-linked network structure, which greatly improves its overall performance.
In addition, we should also note that as the content of epoxy soybean oil increases, the degree of cross-linking of the polyurethane system increases, and the mechanical properties and water resistance of waterborne polyurethane increase. However, the introduction of cross-linking structure will increase the viscosity of the system too fast in the early stage, and it is easy to produce gel phenomenon.