2026-04-14T15:14:11Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/486832021-09-19T18:31:44Zcom_10324_1158com_10324_931com_10324_894col_10324_1242

Cimavilla Román, Paula Santiago Calvo, Mercerdes Rodríguez Pérez, Miguel Ángel 2021-09-17T08:36:49Z 2021-09-17T08:36:49Z 2021 Polymer Testing, 2021, In Press, 107336 0142-9418 https://uvadoc.uva.es/handle/10324/48683 10.1016/j.polymertesting.2021.107336 The modulus build-up and relative density evolution during the reactive foaming of four standard polyurethane formulations was monitored in-situ by Dynamic Mechanical Analysis (DMA) with a customised set-up in parallel plate geometry. The modulus increased from 0.01 MPa in the first minutes to over 1.2 MPa within 20 min. The set-up also enabled the recording of vitrification followed by curing times. These typically occur within 3 min of each other. The results of DMA are corroborated by measurements of the reaction kinetics with Infrared Spectroscopy. This goes to show that the modulus remains nearly unchanged during the stage of swiftest isocyanate conversion, while the point of gel conversion is accompanied by their increase. eng info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ © 2021 Elsevier Attribution-NonCommercial-NoDerivatives 4.0 Internacional Dynamic Mechanical Analysis during polyurethane foaming: Relationship between modulus build-up and reaction kinetics info:eu-repo/semantics/article