Silver-polymer composite materials with antibacterial properties

Abstract

A series of new polyurethane acrylates were prepared by in situ free-radical polymerization of acrylic acid or 2,2bis[5(methacryloyloxyethylcarbonylaminomethyl-1-carbamoyloxymethyl)-3,3-trimethyl-ciclohexyl] propionic acid (UMA-1) into a polyurethane matrix, accompanied by the total/partial ionization of the carboxyl groups from the acrylic component with the amino groups from the macromolecular chain. For a set of samples, silver nitrate was added so that through an in situ electron transfer reaction, atomic silver was formed in the metal particles/polymer composites. The characterization of the polyurethane acrylates and hybrid composites was achieved through thermal methods (TGA) and surface analysis (contact angle), whereas the presence of silver nanoparticles was confirmed by energy-dispersive X-ray (EDX) and UV-vis spectroscopy. The mechanical parameters of the polymeric materials were investigated comparatively to the precursors as well as to the silver/polymer composites by tensile stress. Antibacterial properties of such hybrid composites were determined by using an agar diffusion test against both Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) cultures, the results showing a significant effect of these materials to inhibit the growth of bacteria on surface by silver nanoparticles.