Development and characterization of open cell materials for acoustic applications

Open cell materials are lightweight and multifunctional, capable of absorbing acoustic energy and supporting mechanical load. The acoustic and mechanical performance of open cell materials can be optimized through processing. In this thesis, the relationship between processing parameters and acoustic and mechanical performance is shown for both polypropylene (PP) and aluminium foams. Polypropylene foams are fabricated using a novel method introduced in this work. The method combines compression molding and particulate leaching to fabricate open cell materials. Aluminium foams are fabricated using perforation technique to open interconnected networks in existing closed cell materials. The results from a parametric study showed that both salt size and salt to polymer ratio affected the acoustic and mechanical performance of polymer foams. However, only perforation ratio was shown to affect aluminium foams. The processing relationships and results presented in this thesis will be relevant to the design of new multifunctional open cell foam materials.