Rational design of a polypropylene composite foam with open-cell structure via graphite

conductive network for sound absorption

Abstract:   An exciting result is reported in thisstudy where a polypropylene (PP) foam with a high open-cell content wasachieved by constructing a thermally conductive network for the first time. PPand nano-graphite particles were used as substrate and filler, respectively, toprepare the PP-graphite (PP-G) composite foam by twin-screw blending, hotpressing, and supercritical CO2 foaming. The nano-

graphite particles can effectively adjust the microstructure of the PP-G foam and achieve ahigh porosity. When the amount of nano-graphite is 10.0 wt%, the PP-G foamexhibits optimal sound absorption performance, compression resistance, heatinsulation, and hydrophobic properties. In the human-sensitive frequency rangeof 1000–6000Hz, the corresponding average SAC is above 0.9, and the internal tortuosity is5.27. After 50 cycles of compression, the compressive stress is 980 kPa and theSAC loss is only 7.8%. This study also innovatively proposed a new strategy toachieve the simple and rapid preparation of open-cell PP foams by increasingthe thermal conductivity of the foaming substrate.

Li Z, Yang C, Yan K, Xia M, Yan Z, Wang D, Wang W. Rational design of a polypropylene composite foam with open-cell structure via graphite conductive network for sound absorption. Soft Matter. 2024;20(5):1089-1099.