Paula Cimavilla-Román

Study Of The Cellular Structure Of Rigid Polyurethane Foams Before Cream Time By Cryostatic X-Ray Tomography

Abstract: We report the application of cryogenic X-ray tomography to investigate the cellular structure development of rigid polyurethane foams. Polyurethane foams are produced from the reaction of hydroxyl-containing compounds and isocyanate groups. This leads to a reactive foaming process which progresses until cure. To analyze the structure of these foams over time the reactive process must be stopped. This is achieved by plunging the samples into liquid nitrogen, which freezes the cellular structure of the foams. In order to ensure the stability of the samples, these are kept at -120 °C during the tomography acquisition. Thanks to the reconstruction of the X-ray tomographies, it is possible to visualize the cellular structure of the foams in 3D. The analysis of the tomography provides a precise characterization of the foam morphology and an overview of how cell size, cell density and solid phase thickness evolve during the initial stages of foaming.

Biography: Paula Cimavilla-Román is Ph.D. candidate in Physics at the University of Valladolid. Her work is focused on developing and implementing novel techniques to investigate the complex polymerization and cellular structure development of reactive foams. During the course of her Ph.D., she has worked on research activities involving time-resolved X-ray imaging, Dynamic Mechanical Analysis and Rheology of systems undergoing simultaneous expansion and polymerization as well as X-ray tomography to model the influence of the 3D foam structure on the foams properties.