Development of optimal polymeric foams with superior sound absorption and transmission loss

摘要

The objective of the current research is to propose new polymer composites with optimal acoustic properties. To do so, the ethylene-vinyl acetate foam is employed as the based polymer and the nano silica, nano clay and graphene nanoplatelets are used as extra ingredients. The appropriate amounts of the blowing agent and nano materials are determined using the Taguchi design technique. Using the L-9(3(4)) Taguchi array, different foams are manufactured and their specifications are determined experimentally. Most importantly, the sound absorption and transmission loss of the foams are measured and utilized to specify their noise reduction coefficient (NRC) as well as their average transmission loss (ATL). To maximize the NRC and ATL, optimal formulations are derived based on the Taguchi method. Then the optimal foams are manufactured to characterize their acoustic properties. Experimentations show that both NRC and ATL are respectively improved by 9.76 and 7.98 compared to the best NRC and ATL record of the samples of the Taguchi table. Some new samples with at most one nano material are also produced to study the synergistic effects of the nano materials. Measurements of the acoustic properties of these foams revealed that the combination of the nano materials offers superior acoustic properties.