RT info:eu-repo/semantics/article T1 In-situ understanding of pore nucleation and growth in polyurethane foams by using real-time synchrotron X-ray tomography A1 Pérez Tamarit, Saúl A1 Solórzano Quijano, Eusebio A1 Mokso, Rajmund A1 Rodríguez Pérez, Miguel Ángel K1 Polyurethane K1 Poliuretano K1 Tomography K1 Tomografía K1 Porous polymers K1 Polímeros porosos AB The nucleation and growth of pores in PU foams have been visualized and quantified for the first time in 4D using in-situ tomographic microscopy. Acquiring sequences of 3D images in 156 ms each, we describe homogeneous and heterogeneous nucleation and subsequent bubble growth dynamics for materials with and without nucleating nanoparticles. Exploiting the time resolved tomographic sequences we obtained the bubble nucleation rate, bubble density and size evolution, based on which the diffusion coefficient of gas molecules in polymer can be calculated, evidencing the reduction of diffusivity provoked by the inclusion of nanoparticles. We found that nucleation and growth are in a large extend decoupled in time. PB Elsevier SN 0032-3861 YR 2019 FD 2019 LK https://uvadoc.uva.es/handle/10324/49462 UL https://uvadoc.uva.es/handle/10324/49462 LA eng NO Polymer, 2019, vol. 166. p. 50-54 NO Producción Científica DS UVaDOC RD 27-dic-2024