RT info:eu-repo/semantics/article T1 A new methodology based on cell-wall hole analysis for the structure-acoustic absorption correlation on polyurethane foams A1 Merillas Valero, Beatriz A1 Villafañe González, Fernando A1 Rodríguez Pérez, Miguel Ángel K1 Acoustics K1 Sound absorption K1 Aislamiento acústico K1 Cellular structure K1 Plastic foams K1 Espumas poliméricas K1 Polymers K1 Polimeros y polimerizacion K1 Polyurethane foam K1 Espumas poliméricas de poliuretano - Propiedade mecánicas K1 2201 Acústica K1 2206.10 Polímeros K1 2304.21 Poliuretanos AB Polyurethane foams with a hybrid structure between closed cell and open cell were fabricated and fully characterized. Sound absorption measurements were carried out in order to assess their acoustic performance at different frequency ranges. The cellular structure of these systems was studied in detail by defining some novel structural parameters that characterize the cell wall openings such as the average surface of holes (Sh), the number of holes (h), and the area percentage thereof (%HCW). Therefore, these parameters allow to analyze quantitatively the effect of different structural factors on the acoustic absorption performance. It has been found that the parameters under study have a remarkable influence on the normalized acoustic absorption coefficient at different frequency ranges. In particular, it has been demonstrated that increasing the surface of the holes and the percentage of holes in the cell walls allows increasing the acoustic absorption of these types of foams, a promising statement for developing highly efficient acoustic insulators. Additionally, we could determine that a suitable minimum value of hole surface to reach the highest sound dissipation for these samples exists. PB MDPI SN 2073-4360 YR 2022 FD 2022 LK https://uvadoc.uva.es/handle/10324/62638 UL https://uvadoc.uva.es/handle/10324/62638 LA eng NO Polymers, 2022, Vol. 14, Nº. 9, 1807 NO Producción Científica DS UVaDOC RD 05-jun-2024