Synthesis and mechanical characterization of nanoparticle-infused polyurethane foams. Statistical analysis of foam morphology

Nanocomposite polyurethane (PU) foams filled with different loadings ($0.1$ – $0.7$ wt.%) of nanosized silica (average grain size of $\sim7$ and $12$ nm) and organonanoclay were prepared by the prepolymer method, and their mechanical properties were investigated. A statistical analysis of the size distribution for foam cells was successfully applied in order to characterize their morphology. The developed approach was shown to provide a detailed analysis of the morphology development in PU foams, including the primary cell formation and their subsequent break-up and coalescence. The degree of phase separation in nanocomposite polyurethane foams, which is dependent on the nanofiller, was calculated from the IR spectra. The presence of silica nanoparticles and organoclays gives rise to significant differences in the mechanical (stressstrain) properties of the nanocomposite polyurethane foams relative to the pure polymer.