Antimicrobial polyurethane foams having cationic ammonium groups

Polyurethane foams were prepared by using functional quaternary ammonium monomers to endow the porous materials with antimicrobial properties. For this purpose, tri- and tetra-hydroxyl functional quaternary ammonium compounds were synthesized and used as a triol and tetraol monomer in a polyurethane foam formulation. By this method, the cationic ammonium group is chemically incorporated into the polyurethane backbone. Polyurethane foams containing different amounts of the quaternary ammonium functional group were prepared and characterized by means of Fourier transform infrared spectroscopy, carbon solid-state nuclear magnetic resonance, and scanning electron microscopy. The antimicrobial properties of the cationic polyurethane foams were evaluated toward Escherichia coli and Staphylococcus aureus Gram-negative and Gram-positive bacteria, respectively. Polyurethane foams containing more than 20% of quaternary ammonium component display high antimicrobial activity and can be used for several applications requiring antimicrobial properties.