2024-03-29T06:54:14Zhttps://uvadoc.uva.es/oai/requestoai:uvadoc.uva.es:10324/407062021-06-24T07:47:05Zcom_10324_31661com_10324_952com_10324_894com_10324_1158com_10324_931col_10324_31662col_10324_1242
Highly anisotropic nanocellular polymers based on tri-phasic blends of PMMA with two nucleating agents
Bernardo García, Victoria
Martín de León, Judit
Rodríguez Pérez, Miguel Ángel
One strategy to produce nanocellular polymers is the use of nucleating species to promote nucleation. Whereas two-phase systems are widely studied, tri-phasic blends with two nucleating agents are uncommonly investigated. In this work, nanocellular polymers are obtained using tri-phasic blends of polymethylmethacrylate (PMMA) with two nucleating agents: needle-like sepiolites and a polymethylmethacrylate-polybutylacrylate-polymethylmethacrylate (MAM) block copolymer. Blends of PMMA with different concentrations of MAM and a fixed amount of sepiolites are produced by extrusion. Results show that at low MAM contents (1 wt%), the nucleation is a combination of the action of the two additives, but the addition of sepiolites induces the appearance of anisotropic structures. Meanwhile, at high MAM concentrations (10 wt%), MAM nanostructuration controls the nucleation and sepiolites increase the anisotropy. The alignment of the MAM micelles and the sepiolites in the extrusion direction promotes coalescence in this direction, leading to highly anisotropic nanocellular structures. Mean cell sizes of 100–300 nm and an average anisotropy ratio of 2.77 are obtained thanks to the combined effect of MAM and sepiolites.
2020-04-06T07:35:42Z
2020-04-06T07:35:42Z
2019
info:eu-repo/semantics/article
Material Letters 225 (2019) 126587
0167-577X
http://uvadoc.uva.es/handle/10324/40706
10.1016/j.matlet.2019.126587
126587
Materials Letters
255
spa
info:eu-repo/semantics/openAccess
SI