The role of prepared ZnO nanoparticles on improvement of mechanical and antibacterial properties of flexible polyurethane foams: experimental modeling

The antibacterial polyurethane foam-ZnO nanocomposites with high strength are prepared along with reducing the amount of consumable tin catalyst. The effect of three key parameters on the foams strength (weight percentage of ZnO nanoparticles, isocyanate index, and amount of tin catalyst) is optimized using response surface methodology. The cellular morphology and matrix structure of prepared foams were investigated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy respectively. In addition, using tensile tests, the optimum conditions found for the maximum tensile strength (193.5 kPa) were isocyanate index: 109, tin catalyst: 0.14 g per 100 g polyol, and weight percentage of ZnO nanoparticles: 1.5 with good agreement between the predicted and experimental values. Moreover, the results of compression strength of the samples showed that the resistance to compression of the optimal nanocomposite was increased in comparison with the neat foams. The antibacterial activity of the optimal nanocomposite was investigated against Escherichia coli and Staphylococcus aureus bacteria. Eventually, the results showed that the synthetic foam with optimal conditions in addition to high strength compared to pure foam requires less tin catalyst and has appropriate antibacterial properties.