Merillas Beatriz, Villafañe Fernando, Rodríguez-Pérez Miguel Ángel
Cellular Materials Laboratory (CellMat), Condensed Matter Physics Department, Faculty of Science, University of Valladolid, Campus Miguel Delibes, Paseo de Belén 7, 47011 Valladolid, Spain.
GIR MIOMeT-IU Cinquima-Inorganic Chemistry, Faculty of Science, University of Valladolid, Campus Miguel Delibes, Paseo de Belén 7, 47011 Valladolid, Spain.
Polymers (Basel). 2022 Apr 28;14(9):1807. doi: 10.3390/polym14091807.
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 (), the number of holes (), 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.
制备了具有闭孔和开孔混合结构的聚氨酯泡沫，并对其进行了全面表征。进行吸声测量以评估它们在不同频率范围内的声学性能。通过定义一些表征细胞壁开口的新结构参数，如孔的平均表面积（）、孔的数量（）及其面积百分比（%HCW），详细研究了这些体系的泡孔结构。因此，这些参数能够定量分析不同结构因素对吸声性能的影响。研究发现，所研究的参数在不同频率范围内对归一化吸声系数有显著影响。特别是，已经证明增加孔的表面积和细胞壁中孔的百分比可以提高这类泡沫的吸声性能，这对于开发高效隔音材料是一个很有前景的说法。此外，我们可以确定存在一个合适的孔表面最小值，以使这些样品达到最高的声音消散。
