Fabrication and characterization of waterborne polyurethane/silver nanocomposite foams

Nowadays the waterborne polyurethane (WPU) is a newly developed polymer foam material as a replacement for conventional organic solvent‐based polyurethane (PU). Nevertheless, the WPU foams exhibit some drawbacks such as inferior mechanical strength, low thermal and dimensional stability, which inhibits its large‐scale application at present. So a series of novel WPU/silver nanocomposite foams was successfully prepared by mechanical foaming method. The effect of silver nanoparticles (nano Ag) content on the morphology, thermal behavior, air permeability, water vapor transmission rate (WVT), mechanical, and antibacterial properties of WPU/Ag nanocomposite foams were systematically investigated. The results revealed that the nano Ag were uniformly dispersed in WPU matrix and facilitated cell growth, leading to enhanced mean pore size, thermal stability, air permeability, and WVT value of nanocomposite foams. About 122% improvement in the air permeability and 28% improvement in the WVT value were obtained when the nano Ag content extended from 0 to 4 wt%. It was found that the nano Ag content had great influence on tensile strength and elongation at break. When nano Ag content was 2 wt%, the nanocomposite foam exhibited the maximum tensile strength value of 1.26 MPa. Moreover, because of the addition of nano Ag, the nanocomposite foam showed bacteriostatic rate of 98.23% and 97.38% against Escherichia coli and Staphylococcus aureus, respectively. POLYM. COMPOS., 40:1492–1498, 2019. © 2018 Society of Plastics Engineers