The Influence of Aging on the Structure and Properties of Composite Materials Based on Polyurethane and Silver Nanoparticles

The aging processes and their influence on structure, thermophysical and antimicrobial properties of polymer nanocomposites based on segmented polyurethane and silver nanoparticles were studied. It was established that an increase in the intensity of intermolecular interactions of polyurethane occurred regardless of the concentration of silver in the silver nanoparticles due to a change in the packing of macromolecules. It was shown that in the process of aging of composites, the effective size of crystallites of polymer matrix decreases and varies in the range of 1.35-1.50 nm. The most pronounced effect of aging is manifested on the melting temperatures of the crystalline phase of polyurethane and the degree of crystallinity. It was found that polyurethane-silver nanoparticle composites exhibit a very high inhibitory capacity against Staphylococcus aureus, Escherichia coli, and Candida albicans. It is shown that aging processes do not affect the antimicrobial characteristics of the studied materials, which indicates their stability. Due to their unique characteristics, synthesized nanocomposite films can be promising for use as antimicrobial coatings in various applications.