RT info:eu-repo/semantics/article
T1 Anisotropy in nanocellular polymers promoted by the addition of needle‐like sepiolites
A1 Bernardo García, Victoria
A1 Martín de León, Judit
A1 Rodríguez Pérez, Miguel Ángel
AB This work presents a new strategy for obtaining nanocellular materials with high anisotropy ratios by means of the addition of needle‐like nanoparticles. Nanocellular polymers are of great interest due to their outstanding properties, whereas anisotropic structures allow the realization of improved thermal and mechanical properties in certain directions. Nanocomposites based on poly(methyl methacrylate) (PMMA) with nanometric sepiolites are generated by extrusion. From the extruded filaments, cellular materials are produced using a two‐step gas dissolution foaming method. The effect of adding various types and contents of sepiolites is investigated. As a result of the extrusion process, the needle‐like sepiolites are aligned in the machine direction in the solid nanocomposites. Regarding the cellular materials, the addition of sepiolites allows one to obtain anisotropic nanocellular polymers with cell sizes of 150 to 420 nm and cell nucleation densities of 1013–1014 nuclei cm−3 and presenting anisotropy ratios ranging from 1.38 to 2.15, the extrusion direction being the direction of the anisotropy. To explain the appearance of anisotropy, a mechanism based on cell coalescence is proposed and discussed. In addition, it is shown that it is possible to control the anisotropy ratio of the PMMA/sepiolite nanocellular polymers by changing the amount of well‐dispersed sepiolites in the solid nanocomposites.
SN 0959-8103
YR 2019
FD 2019
LK http://uvadoc.uva.es/handle/10324/40710
UL http://uvadoc.uva.es/handle/10324/40710
LA spa
NO Polymer InternationalVolume 68, Issue 6, 2019
DS UVaDOC
RD 27-dic-2024