Waterborne polyurethane composites with antibacterial activity by incorporating p-BzOH intercalated MgAl-LDH

In this work, we used p-hydroxybenzoic anionic intercalated MgAl-layered double hydroxides (MgAl-(p-BzOH)-LDH) as a filler to modify waterborne polyurethane, and successfully synthesized novel WPU/MgAl-(p-BzOH)-LDH composites. CO32--type MgAl-LDH was firstly synthesized via hexamethylenetetramine hydrolysis method and then was transferred to p-BzOH-intercalated MgAl-LDH by ion exchange. The nanostructured MgAl-(p-BzOH)-LDH was then grafted by isophorone diisocyanate (IPDI), forming [MgAl-(p-BzOH)-LDH]NCO complex with NCO group on the surface, which promotes its homogeneous dispersion in WPU matrix through chemical bonding. The mechanical properties and water resistance of the composites were improved upon loading the MgAl-(p-BzOH)-LDH in certain levels. Furthermore, the composites can slowly release p-hydroxybenzoic anionic into the surrounding environment, and thus exhibit significant antibacterial activity towards G(_) Escherichia coli and G(+) Staphylococcus aureus.