Improved the sound insulating properties of polystyrene through using organically modified montmorillonite

The alleviation of the transmission for noise by using sound insulation materials has been regarded as an efficient route to control noise. In this work, the reinforcing effect on the sound insulating properties of polystyrene (PS) was successfully realized by using cetyltrimethylammonium bromide (CTAB) organically modified montmorillonite. The micrometer montmorillonite (MMT) was firstly organic modified by CTAB and then was melt blended with PS matrix to obtain high sound insulation polymer composites. X-ray diffraction results revealed that CTAB intercalation into MMT lamellar structure, leading to the increased lamellar space of the organically modified montmorillonite (OMMT). Moreover, the OMMT lamellar spacing was further enlarged by the intercalation of PS molecular chains. The sound insulation properties of all samples were tested by a four-microphone impedance tube. The average sound transmission loss (STL) of PS composites increased with the amount of OMMT. The average STL of PS/OMMT composite with the thickness of only 1.8 mm can reach to 35.46 dB when the weight fraction of OMMT was 30%, which is 36.0% higher than that of pure PS (26.08 dB). The sample thickness increased to 3.8 mm and the average STL up to 47.78 dB. Meanwhile, the storage modulus and thermal stability of PS were also enhanced by incorporating OMMT. This fabricating technique can provide a novel method to obtain low-cost and low-weight acoustic materials with high sound insulating properties.