[article]
| Titre : |
Microcellular thermosetting polyurethane foams |
| Type de document : |
texte imprimé |
| Auteurs : |
C. Brondi, Auteur ; M. R. Di Caprio, Auteur ; Ernesto Di Maio, Auteur ; T. Mosciatti, Auteur ; S. Cavalca, Auteur ; V. Parenti, Auteur ; S. Iannace, Auteur |
| Année de publication : |
2020 |
| Article en page(s) : |
p. 326-330 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Mousses microcellulaires
Mousses plastiques
Polyuréthanes
Procédés de fabrication
|
| Index. décimale : |
668.4 Plastiques, vinyles |
| Résumé : |
Thermosetting polyurethane foams are nowadays produced with typical bubble size, d > 150 μm, with plenty of room for improvement towards the cellular structure refinement, to gain, among others, in the thermal insulation performances. We herein report a first example of a microcellular thermosetting polyurethane foam, i. e. with bubble size below 5 μm, produced via the gas foaming technology. In particular, high-pressure CO2, N2 and their mixtures were utilized as blowing agents: solubilized separately into the polymer precursors, they were brought into a supersaturated state by a pressure reduction to induce the bubble nucleation and growth. To achieve microcellular foams, we made use of a novel two-stage pressure reduction program, concurrent to the polymer curing. The first stage is a pressure quench O (10–2 s) from the saturation pressure to an intermediate pressure to induce the nucleation of a large amount of dense bubbles. The second stage is a slow O (102 s) further pressure decrease to ambient pressure, allowing for a slow bubble growth, designed to reach ambient pressure exactly when the curing reached completion. |
| DOI : |
https://doi.org/10.3139/217.3936 |
| En ligne : |
https://drive.google.com/file/d/1ElR0vxpReESyOoYTj3SwEYdYLtC9p09x/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34497 |
in INTERNATIONAL POLYMER PROCESSING > Vol. XXXV, N° 3 (07/2020) . - p. 326-330
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Microcellular thermosetting polyurethane foams in INTERNATIONAL POLYMER PROCESSING, Vol. XXXV, N° 3 (07/2020)
