2026-04-28T19:31:43Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/258782021-06-30T09:37:48Zcom_10324_31661com_10324_952com_10324_894com_10324_1158com_10324_931col_10324_31662col_10324_1242

Bernardo García, Victoria Martín de León, Judit Laguna Gutiérrez, Ester Rodríguez Pérez, Miguel Ángel 2017-09-24T14:40:59Z 2017-09-24T14:40:59Z 2017 European Polymer Journal, 2017, vol. 96. p. 10–26 http://uvadoc.uva.es/handle/10324/25878 10.1016/j.eurpolymj.2017.09.002 In this work, a new system based on poly(methyl methacrylate) (PMMA) sepiolite nanocomposites that allow producing nanocellular polymers by using the gas dissolution foaming technique is described. Nanocomposites with different nanoparticle types and contents have been produced by extrusion. From these blends, cellular materials have been fabricated using the so-called gas dissolution foaming method. An extensive study of the effect of the processing parameters (saturation pressure and foaming temperature) on the cellular materials produced has been performed. Results showed that among the three sepiolites used, only those modified with a quaternary ammonium salt are suitable for being used as nucleating agents in PMMA. With these nanoparticles bimodal cellular polymers, with micro and nanometric cells, have been produced. Cell sizes in the range of 300–500 nm and cell densities of the order of 1013–1014 nuclei/cm3 have been obtained in the nanocellular region. A foaming temperature of 80 °C and a wide range of saturation pressures (between 10 and 30 MPa) and low particle contents (between 0.5 and 1.5 wt%) allow obtaining these materials. Furthermore, it has been found that cell size in the nanometric population can be controlled by means of the particles content; a reduction in the cell size is obtained when the particles content increases. Finally, results indicate that an increase in the foaming temperature leads to cellular nanocomposites with lower relative densities (below 0.21) and larger cell sizes (above 450 nm). Financial support from FPU grant FPU14/02050 (V. Bernardo) from the Spanish Ministry of Education and Junta of Castile and Leon grant Q4718001C (J. Martín-de León) is gratefully acknowledged. Financial assistance from MINECO, FEDER, UE (MAT2015- 69234-R) and the Junta de Castile and Leon (VA011U16) are gratefully acknowledged. We would also like to thank the company Tolsa (Madrid, Spain) for supplying the sepiolites of this study application/pdf eng Elsevier info:eu-repo/semantics/restrictedAccess Elsevier PMMA-sepiolite nanocomposites as new promising materials for the production of nanocellular polymers info:eu-repo/semantics/article https://www.sciencedirect.com/science/article/pii/S0014305717310017?via%3Dihub SI