Physical Foaming of an Ethylene/Acrylic Acid/n-Butyl Acrylate Ionomer with Carbon Dioxide

Thermal transitions of and the physical foaming of an ethylene/acrylic acid/n-butyl acrylate ionomer with carbon dioxide have been explored. Foaming experiments were conducted using 1 mm thick films of the polymer by saturation at 100, 120, 140, and 160 °C at 120, 140, 160, 180, 200, and 220 bar in CO2 followed by rapid depressurization. The foam morphologies that develop have been mapped along the rigidity reduction path of the polymer in CO2...