Synthesis and Application of Antibacterial Poly(ionic liquid)-Based Waterborne Polyurethanes Modified with Siloxane

Waterborne polyurethane (WPU) coatings have gained numerous attentions and popularity due to their outstanding structural tunability and environmental friendliness, but their applications are often limited due to their susceptibility to harbor bacteria and poor water resistance. Herein, a group of water-resistant antibacterial WPU coatings were developed by simultaneously incorporating imidazolium cations and siloxane groups into the WPU backbone. Utilizing imidazolium cations, the resulting WPU films and coatings demonstrated exceptional antibacterial efficacy against Escherichia coli and Staphylococcus aureus, with rates exceeding 99.99%. The incorporated siloxane groups are prone to migrate to the surface of the coatings/films due to their low surface free energy, thus significantly promoting the antifouling properties and hydrophobicity of the resulting WPU films/coatings.