Microstructure and sound absorption of porous copper prepared by resin curing and foaming method

Porous copper was prepared by a rosin curing and foaming method using a thermosetting phenolformaldehyde resin as a binder and C5H10N6O2 as a foaming agent. The effects of resin content On the pore structure and sound absorption of the porous copper were investigated. The results show that the porosity and fractal dimension increase as the resin content increases, whereas the airflow resistivity and sound absorption coefficient decrease. The results also indicate that the sound absorption coefficient is affected by the pore size distribution. Sound absorbers consisting of porous copper prepared by this method exhibit a greater sound absorption capacity and higher average absorption coefficients than those of lotus-type porous copper. It is suggested that porous copper prepared by the proposed method could be developed as an efficient sound absorbing material. (C) 2014 Elsevier B.V. All rights reserved.