Evaluation of Sound Absorption Coefficient of Various Proportions of Nanocomposite Polystyrene/Nanoclay at Different Frequencies

One way to control sound is the use of sound absorbing materials (especially polymer foams). In recent years, nanocomposite polymers have received much attention because of the improved properties of polymers. In this study, the effects of nanoclay on sound absorption coefficient of polymeric materials have been investigated.
Nanocomposite polystyrene/clay was synthesized using in-situ polymerization technique. For comparison of absorption coefficient, styrene polymer was also synthesized. The synthesized compounds were converted into foam using compression molding. Sound absorption coefficient was determined using impedance tube.
Findings: Absorption coefficient of styrene polymer had a peak in the frequency range of 2000 to 4000 Hz. The maximum absorption coefficient (0.75) was observed at a frequency of 2500. With 0.5% nanoclay, the highest absorption coefficient at the frequency of 2500 Hz reached a rate of 0.89. In 3% nanoclay, maximum absorption coefficient at the frequency of 3150 Hz was 0.9. In addition, in 7% nanoclay, maximum absorption coefficient (0.54) was observed at the frequency of 2000 Hz.
With the addition of 0.5% nanoclay to polymer, only the height of the frequency peak increased. In 3% nanoclay, in addition to increasing of absorption coefficientý, the location of the frequency peak shifted. In 7% nanoclay, with the variation in the frequency peak range, an increase was observed in the absorption coefficient.