RT info:eu-repo/semantics/article
T1 The mechanics of solid-state nanofoaming
A1 Van Loock, Frederik
A1 Bernardo García, Victoria
A1 Rodríguez Pérez, Miguel Ángel
A1 Fleck, Norman A.
AB Solid-state nanofoaming experiments are conducted on two polymethyl methacrylate (PMMA) grades of markedly different molecular weight using CO2 as the blowing agent. The sensitivity of porosity to foaming time and foaming temperature is measured. Also, the microstructure of the PMMA nanofoams is characterized in terms of cell size and cell nucleation density. A one-dimensional numerical model is developed to predict the growth of spherical, gas-filled voids during the solid-state foaming process. Diffusion of CO2 within the PMMA matrix is sufficiently rapid for the concentration of CO2 to remain almost uniform spatially. The foaming model makes use of experimentally calibrated constitutive laws for the uniaxial stress versus strain response of the PMMA grades as a function of strain rate and temperature, and the effect of dissolved CO2 is accounted for by a shift in the glass transition temperature of the PMMA. The maximum achievable porosity is interpreted in terms of cell wall tearing and comparisons are made between the predictions of the model and nanofoaming measurements; it is deduced that the failure strain of the cell walls is sensitive to cell wall thickness
SN 1364-5021
YR 2019
FD 2019
LK http://uvadoc.uva.es/handle/10324/40716
UL http://uvadoc.uva.es/handle/10324/40716
LA spa
NO Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences Volume 475, Issue 2230, 2019
DS UVaDOC
RD 25-nov-2024