Synthesis and cryogenic mechanical properties of CO2-blown carbon-reinforced polyurethane foam

In the present study, carbon-nanotube-polyurethane foams were synthesized by adding (0.02, 0.1, and 0.3 wt%) carbon nanotubes during the polymerization reaction between polyol and isocyanate liquids. After the synthesis process, the microstructural cell morphology of the carbon-nanotube-polyurethane foams, based on the amount of carbon nanotubes, was observed using field emission scanning electron microscopy. To evaluate the mechanical characteristics of the carbon-nanotube-polyurethane foams, temperature-dependent (20°C, −90°C, and −163°C) compressive tests were performed, and the results were compared to those of the pure polyurethane foam to verify the effectiveness of the developed carbon-nanotube-polyurethane foams. Specifically, the effects of the weight percent of carbon nanotubes, density, and temperature on the overall behavior of the carbon-nanotube-polyurethane foams were considered. Finally, the permanent deformation ratio and material failure characteristics were investigated. The results showed that the cell morphology and compressive strength of the carbon-nanotube-polyurethane foam with 0.02 wt% carbon nanotubes were superior to those of pure polyurethane foam, and these properties showed a significant dependence on the weight percent of carbon nanotubes, test temperatures, and the density.