Sound transmission loss through nanoclay-reinforced polymers

Abstract

Excessive noises frequently disturb people by fatigue, reduced working efficiency and health system disorders. An efficient method to reduce noise is to find and apply sound insulation materials. Research and development on nanocomposites as a sound insulation material are quite advanced. In this study, acrylonitrile–butadiene–styrene (ABS)/nanoclay nanocomposites were fabricated at 2, 4, 6 and 8 wt% of organically modified clay using a twin screw extruder. Sound transmission loss (STL) was determined by impedance tube device to evaluate the sound insulation properties of the samples. The results showed that ABS/clay (4 wt%) and (8 wt%) could improve the STL of virgin ABS by 6–20 and 4–5 dB at high (1600–6300 Hz) and low (700–1600 Hz) frequency ranges, respectively. In addition, the physical and mechanical characteristics of the nanocomposites were evaluated at various filler loadings to compare with sound insulation efficiency. Modulus of elasticity was improved in presence of nanoclay in accordance with increasing STL at low sound frequency. The surface density of samples varied slightly with increases in nanoclay content; therefore, it could not be a leading parameter to influence STL at all frequencies. State of dispersion in nanocomposites was investigated using X-ray diffraction and transmission electron microscopy. It was found that a sample containing 4 wt% of nanoclay showed the best dispersion accompanied by the best soundproofing efficiency.