In this thesis, in order to enhance acoustic properties of polyurethane foam, small amount of carbon-nanotubes and silicon oxide nanopowders were added to the polyol-isocyanate composition. In this thesis, acoustic properties of added small amount of carbon-nanotubes and silicon oxide nanopowders (S-type, P-Type) to the polyurethane composition were determined. By adding CNTs and/or nano-silica in the form of powder or liquid at different concentrations up to 2% within the PU composition to improve the sound absorption were investigated in the frequency range up to 6400 Hz. In this thesis, both CNTs and nano-silica (SiO2) particles were added with different quantities to the isocyante-polyol composition. The properties, especially the sound absorption, were studied for all the prepared samples and results were investigated to come up with the best nanocomposites that can be applied for sound absorption application at the desired operating frequency.
The results of sound transmission loss and absorption coefficient were determined and compared. As expected, it was found that most of samples were either good in STL or good in absorption. However, some combinations can achieve a balance of performance in both categories. |