2026-04-27T20:08:17Zhttps://uvadoc.uva.es/oai/request

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

00925njm 22002777a 4500 dc Cimavilla Román, Paula author Santiago Calvo, Mercerdes author Rodríguez Pérez, Miguel Ángel author 2021 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. Polymer Testing, 2021, In Press, 107336 0142-9418 https://uvadoc.uva.es/handle/10324/48683 10.1016/j.polymertesting.2021.107336 Dynamic Mechanical Analysis during polyurethane foaming: Relationship between modulus build-up and reaction kinetics