2024-03-28T17:30:10Zhttp://uvadoc.uva.es/oai/requestoai:uvadoc.uva.es:10324/258862021-06-24T07:45:54Zcom_10324_31661com_10324_952com_10324_894com_10324_1158com_10324_931col_10324_31662col_10324_1242
Rigid polyurethane foams with infused nanoclays: Relationship between cellular structure and thermal conductivity
Estravís Sastre, Sergio
Tirado Mediavilla, Josias
Santiago Calvo, Mercerdes
Ruiz Herrero, José Luis
Villafañe González, Fernando
Rodríguez Pérez, Miguel Ángel
Producción Científica
A water blown rigid polyurethane (PU) formulation has been used to manufacture cellular
nanocomposites containing different concentrations of montmorillonite nanoclays. The PU
foams have been produced using a low shear mixing technique for dispersing the nanoclays
and by reactive foaming to generate the cellular structure. A detailed characterization
of the cellular structure has been performed. The effect of the nanoparticles on the
reaction kinetics and the state of intercalation of the nanoparticles in the foams has been
analyzed. The thermal conductivity and extinction coefficient of the different materials has
been measured and the results obtained have been correlated with the materials structure.
A strong reduction of cell size and modifications on cell size distribution, anisotropy ratio
and fraction of material in the struts has been detected when the clays are added. In addition,
a reduction of the thermal conductivity has been observed. Different theoretical models
have been employed to explain thermal conductivity changes in terms of structural
features. It has been found that, in addition to the modifications in the cellular structure,
changes in the extinction coefficient and thermal conductivity of the matrix polymer play
an important role on the final values of the thermal conductivity for these materials.
We would like to acknowledge to Mr. Vela and Mr. Ferrer, from BASF Española S.L., for supplying the PU formulation employed in this research. The authors are grateful to the Spanish Ministry of Science and Education which supported this work with a FPU Grant Ref-AP-2008-03602 given to Mr. Estravís. In addition, Financial assistance from the Spanish Ministry of Science and Innovation, FEDER program (MAT 2012 – 34901 and MAT2015-69234-R), the Junta de Castile and Leon (VA035U13) and the EU Commission (FP7 program, EC project NanCore number 214148) is acknowledged.
2017-09-24T15:22:53Z
2017-09-24T15:22:53Z
2016
info:eu-repo/semantics/article
European Polymer Journal 80 (2016) 1–15
http://uvadoc.uva.es/handle/10324/25886
eng
http://linkinghub.elsevier.com/retrieve/pii/S0014305716302968
info:eu-repo/grantAgreement/EC/FP7/214148
info:eu-repo/semantics/restrictedAccess
Elsevier
application/pdf
Elsevier
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Hispana
TEXT
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UVaDOC. Repositorio Documental de la Universidad de Valladolid
http://uvadoc.uva.es/handle/10324/25886