POLYVINYL ALCOHOL - MELAMINE FORMALDEHYDE RESIN COMPOSITE AND NANOCOMPOSITES WITH Ag,TiO2, ZnO NANOPARTICLES AS ANTIMICROBIAL FILMS, COATINGS AND SPRAYS

Rita Kakkar, Kalpana Madgula, Y. V. Saritha Nehru, Raj M Shailaja, B. Sreedhar
2014
Melamine formaldehyde resin, MFR, is generally formed in a two stage process by the reaction of melamine and formaldehyde. The first stage reaction is carried out at about 70° - 80°C and pH 9-10; and the second stage involves subsequent polycondensation of the products in an acid medium. In this work, reaction is carried out till the first stage only. Thus, prepared MFR when blended in small proportion into PVA matrix in-solubilises PVA, forming a well defined PVA-MFR composite. The blend can
more » ... cast into films of desired thickness and strength. Nanoparticles of Ag, ZnO and TiO2 were prepared and characterised. Each of the prepared nanoparticles was first blended into aqueous PVA, then blended with MFR, and nanocomposite films obtained. The films were subjected to TGA, FTIR and antimicrobial studies. The PVA-MFR composite films are found to have a high level of antimicrobial activity. Nanocomposites have enhanced antimicrobial activity due to antimicrobial property of nano Ag/ZnO/TiO2 in them. The activity is high, especially against highly resistant gram positive bacteria like Staphylococcus Aureus and Bacillus. The composite has good binding properties, forming stable, chemically resistant, coatings on fabric, paper, glass, polyester etc, rendering them antimicrobial. These films and coatings retain their antimicrobial activity over long period of time. Nano silver immobilised on antimicrobial PVA-MFR, could probably be an effective patch for wound dressings, and surgical mask, which are in great demand. A fine coating of the composite on medical devices can decrease the incidence of medical device related infections.
doi:10.17628/ecb.2014.3.1088-1097 fatcat:h44mnpu3ffewrcitgr6rxfs42a