Acoustic and Mechanical Properties of Polystyrene Composite Filled with Primary Sludge and Boiler Ash from Pulp Mill

The search for green composite for sound-absorbing material has increased a significant interest. In this study, polystyrene (PS) composite foam filled with primary sludge and boiler ash from pulp mill was produced. The product was characterized using analytical techniques such as FTIR, XRD, SEM, TGA, and DSC, while the mechanical properties and sound-absorbing coefficient were analyzed regarding ASTM D 2240 and ASTM E-1050-98, respectively. The results showed that the sludge has 1β crystalline polymorph cellulose from the pulp. The chemical reaction can be seen by the chemical bond formed during the mixing process. The peak expansion occurred at 1600.44 cm-1 indicating the presence of a C=C functional group of maleic anhydride with polymer and filler. SEM images showed that the filler was distributed and dispersed into the polymer matrix and no agglomeration was produced. The sound-absorbing composites had complied ISO 11654:1997 regarding the sound absorption coefficient rating level on materials for rooms with sound absorption classes D and C with the value of α 0.328-0.793.