The effects of silica aerogel on the rheological behaviour and polymer matrix structure of Rigid Polyurethane foams
| Autor: | Paula Cimavilla-Román, Saul Perez-Tamarit, Anja Vananroye, Paula Moldenaers, Miguel Ángel Rodriguez-Pérez |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Science & Technology
Polymers and Plastics Polyurethane foams Polyurethane foam Silica aerogel Organic Chemistry Polymer Science General Physics and Astronomy MECHANICAL-PROPERTIES NANOCOMPOSITES Reología Aerogel de sílice Physical Sciences Materials Chemistry Espumas de poliuretano Rheology Reaction kinetics X-ray tomography NANOFILLERS |
| Zdroj: | UVaDOC. Repositorio Documental de la Universidad de Valladolid instname |
| DOI: | 10.1016/j.eurpolymj.2022.111398 |
| Popis: | Producción Científica The incorporation of silica aerogel particles into the isocyanate used to prepare Rigid Polyurethane composite foams drastically modifies its rheological behaviour. The isocyanate changes from being a Newtonian fluid of constant viscosity (0.3 Pa s at 25 °C) to a non-linear power-law material with complex viscosity decreasing from 104 to 101 Pa s with a slope −1 versus frequency. The change in response is caused by the formation of a percolated network of particles at contents above 2.5 wt% of aerogel. Moreover, the addition of aerogel significantly slows down the modulus-build up kinetics and vitrification of the matrix by approximately 4.5 min with every 1 wt% of aerogel added. For the foam with 3.0 wt% of aerogel, the combination of high viscosity at early reaction times coupled with the slow modulus build-up impedes the drainage which leads to a decrease in the fraction of material in the struts of the matrix. Junta de Castilla y Leon (project VA202P20) Ministerio de Ciencia, Innovación y Universidades (projects RTI2018-098749-B-I00 and RTI2018 - 097367-A-I00) |
| Databáze: | OpenAIRE |
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