Sound absorption characteristics of polymer microparticles

Abstract

A sound absorption material composed of polymer microparticles and polyurethane (PU) foam with certain geometry cavum has been developed. Its soundabsorbing characteristic was investigated in the impedance tube, according to transfer function method. Measurements show that polymer microparticles have remarkable effect on the absorption performance of the composite material because of their microstructures and features. Several models established for acoustic properties have been adopted to fit the experimental data. The results show that these models fail to predict accurately the acoustic properties of the materials. The sound energy attenuation in polymer microparticles material may most likely consist of two parts, viscous attenuation of air inside the pores and the friction energy caused by the oscillation of polymer particles.

Polyurethane/poly(vinylidene fluoride)/MWCNT composite foam for broadband airborne sound absorption

“…The addition of magnesium hydroxide fillers in PU foams also showed an increase in lower frequency sound absorption, where it was believed that the fillers worked as internal inclusions to dampen the acoustic waves . In a similar fashion, the addition of polymer particles in PU foams was reported to increase the lower frequency sound absorption due to the vibration of particles in the lower frequency range . In an effort to decrease the use of petrochemicals, natural fibers and waste were used as additives including adding tea leaf fibers for increasing the sound absorption property in a wide‐frequency range and bamboo leaves for increasing the lower frequency sound absorption.…”

Multi-Objective Optimization of Acoustical Properties of PU-Bamboo-Chips Foam Composites

“…It turned out that both nanoparticles gave rise to considerable improvement in sound absorption of PU foams and MWNTs were observed to achieve the most satisfied results. Polymer microparticles with different structures, sizes scales and size distributions were enclosed in PU foams by Zhou et al (2006) and the sound absorption characteristics of PU composites were greatly improved by incorporating the polymer microparticles. Flexible PU foams filled with three different fillers namely nano silica, crumb rubber and nano clay were prepared to study their effects on sound absorption at low frequency range by Gayathri et al, and maximum sound absorption coefficient of 80% was obtained at 1.4% weight concentration of all the three fillers (Gayathri et al, 2013).…”

Preparation and Properties of Foamed Cellulose-Polymer Microsphere Hybrid Materials for Sound Absorption

“…These structures were demonstrated to improve the sound absorption coefficients (Liu et al 2013). The elastic hollow polymer microsphere (PM) was reported to have sound absorption superiority in a low sound frequency range (250 Hz to 1500 Hz) but not at high sound frequencies (≥1500 Hz) (Lauriks et al 1989;Hong 2004;Zhou et al 2004). Moreover, the cellulose fiber-based network exhibits outstanding sound absorbing property at high sound frequencies (≥1000 Hz) but not at low sound frequencies.…”