Foaming behavior of silicone/fluorosilicone blends

An alternative approach, based on vinyl-PDMS/Fluorosilicone blends, has been developed to improve the CO2 foaming behavior of silicone elastomers. For this purpose, a dynamic crosslinking process has been used to compatibilize these silicone blends and to improve their strain hardening behavior under biaxial deformation. As a result, fine cells (65 μm) have been achieved using gaseous CO2 in a one-step batch foaming process. Actually, the dispersed fluorosilicone domains act as nucleating sites allowing the formation of higher nuclei densities which reduce the overall bubble size by competitive nuclei growth. This new formulation strategy has allowed us to develop silicone foams with equivalent properties (cell and foam densities) to foams prepared by supercritical CO2.