A parametric study into the morphology of polystyrene-co-methyl methacrylate foams using supercritical carbon dioxide as a blowing agent

In this study the foaming of poly(styrene-co-methyl methacrylate) (SMMA) using supercritical carbon dioxide is investigated. The effect of different foaming parameters such as temperature and pressure is studied in a quantitative and systematic way, with the aim to control and predict the resulting foam morphology. It is shown that once the polymer properties, such as the glass transition temperature and the solubility of CO2 are known, full control of the desired foam morphology can be obtained by a proper selection of temperature, pressure and depressurization rate.