Development, characterization, and modeling of environmentally friendly open-cell acoustic foams

This study shows the development of new polymeric open-cell foams from polypropylene (PP) and polylactide (PLA) resins with a focus on sound absorption properties and modeling of these foams. The objective is to develop new environmentally friendly foams to replace the existing non-recyclable Polyurethane foams are currently used for sound insulation in industry. Through this research, open-cell foams of about 90% porosity were fabricated from PP and PLA. These resins were selected since PP is a recyclable thermoplastic polymer, and PLA is a bio-based thermoplastic polymer made from renewable resources. Polyurethane (PU) foam which is currently used for sound absorption and noise control in industry was compared to the fabricated PP and PLA foams. As the first attempt to fabricate environmentally friendly acoustic foams, the resulting foam structures show improved properties as compared to the existing materials. The average absorption of PP and PLA foams fabricated is in the range of 0.42-0.55 which is comparable or even higher than the average absorption of PU foam. To better understand the effect of structural and material properties on sound absorption and further improve the acoustic performance of bio-based foams, an analytical model based on Johnson-Champoux-Allard model was used to numerically simulate the acoustic performance of foams under study. POLYM. ENG. SCI., 2013. (c) 2013 Society of Plastics Engineers