Acoustic properties of polyurethane compositions enhanced with multi-walled carbon nanotubes and silica nanoparticles

In this study, in order to enhance acoustic properties of polyurethane (PU) foams multi-walled carbon nanotubes (MWCNT) and/or silica nanoparticles were added to polyol-isocyanate composition up to 2wt%, and acoustic properties of polyurethane foam samples with small amount of carbon nanotubes and silica nanoparticles (spherical and/or amorphous types) were determined in the frequency range from 50Hz up to 6400Hz. Acoustic properties, especially absorption coefficient of the produced samples were measured for all the prepared samples and results were investigated to come up with the best polyurethane samples that can be applied for sound absorption application at the desired frequency range. It was found that double combination of carbon nanotubes and silica nanoparticles, especially 0.7wt% carbon nanotubes and 0.2wt% spherical silica nanoparticle added polyurethane composition has better sound absorption ratio overall all frequencies levels compared to the other samples. Thus, it is possible to obtain polyurethane nanocomposite with a higher amount of carbon nanotube by weight at the same time enhancing sound absorption properties. Moreover, there is a synergic effect between carbon nanotubes and silica nanoparticles when mixed and added into polyurethane matrix at predetermined levels to get enhanced acoustic response with a higher level of carbon nanotube in polyurethane foam.