Structure and Bactericidal Properties of Polymer Composites Derived from Melamine-Formaldehyde Polymer and Silver Nanoparticles Formed in situ

Abstract

Nanocomposites derived from a cross-linked melamine-formaldehyde polymer matrix and silver nanoparticles (AgNP) were prepared in situ. An interaction between Ag + ions and AgNP with fragments of the 1,3,5-triazine polymer matrix was established. The mean diameter of the AgNP consisting of nanocrystal aggregates in the nanocomposites did not exceed 60 nm and was independent of the type of silver precursor. The polymer composite nanosystems display strong bactericidal activity.A current trend in the development of polymer composite materials involves the use of nanostructurized components. Special attention has been given to the development of their bactericidal properties [1,2]. In the overwhelming majority of such materials, silver-containing fillers, metallic silver nanodispersions, and silver derivatives are used as the active component [3]. Among the variety of polymers finding use in such materials (polyurethanes, polyethers, polyamides, polyacrylates, and polysiloxanes [2]), considerable promise is shown by melamine-formaldehyde polymers (MFP) possessing valuable properties such as ease of preparation, good physical and mechanical indices, good chemical stability, and good resistance to degradation upon storage and use. However, there have been only very few reports on the preparation and use of polymer composites derived from MFP and silver. Trogolo and Barry [4] obtained a composite by the introduction of a dispersion of a silver-containing zeolite into a solution of a melamine-formaldehyde oligomer (MFO) with subsequent deposition of the reaction mixture onto a prepared surface with hardening at 100-250°C and 3-30 MPa over 10-60 min. Kim [5] has reported that introduction of a dispersion of stabilized silver nanoparticles in amounts up to 3 mass % into a reaction mixture derived from MFO and subsequent hardening also gave a polymer coating having bactericidal activity.MFP structurally-modified by thiourea [6,7] and tetraoxalylethylenediamine [7] yield polymers capable of forming complexes with Ag + ions, thereby permitting the removal of such ions or effect their concentration. However, there is no information in the literature on the complexation activity of the melamine fragments (2,4,6-triamino-1,3,5-triazine) of the MFP matrix although complexes of melamine with Ag + ions are quite well known [8,9].

Synthesis and characterization of lignin–melamine–formaldehyde resin

“…6,7 Melamine-formaldehyde (MF) resins are widely used because of their low cost, versatility, and many applications such as decorative panels, leather tanning, coating, and materials. 8,9 MF is also used in the electric domain. 10 Several researchers have tried to replace a part of the melamine in the MF resins by a biodegradable material.…”