Releasing of zinc ions from modified zinc oxide surfaces for improvement chemical crosslinks and antibacterial properties of acrylonitrile butadiene rubber films

Abstract

Acrylonitrile butadiene rubber (NBR) films filled with zinc oxide (ZnO) were prepared via latex mixing. The ZnO of commercial ZnO (ZnOWH), ZnO nanoparticles (ZnOnap), ZnOnap-coated with calcium carbonate (ZnOnap-C), and titanium dioxide (ZnOnap-T) were investigated, and the mechanical and dynamic mechanical properties, crosslink density, and antibacterial activity of the resultant films were explored. The study found that the particle size and distribution of ZnO in the NBR films played a significant role in enhancing their properties. The incorporation of ZnOnap resulted in a greater enhancement in the properties of the composite film than the ZnOWH microparticles, with the greatest enhancement achieved with ZnOnap-C. Furthermore, the composite films filled with 1 phr of ZnOnap-C exhibited 99.9% bacterial reduction efficacy against Staphylococcus aureus and Escherichia coli according to ISO 22196:2011 due to the release of reactive oxygen species and zinc ions across the rubber film layers to the bacterial surfaces. In addition, the bactericidal efficacy on the surface of the composite films was investigated by varying the contact kill times in accordance with ASTM D7907-14. The addition of ZnOnap-C at 4 phr reduced both bacterial levels by 92.00 and 51.85%, respectively, within 30 min. Hence, this research aims to contribute to developing new medical disinfection products, such as medical gloves and multipurpose rubber sheets.

Keywords

• polymer composites
• material testing
• industrial application
• recycling
• rubber