Generation of Microcellular Foams by Supercritical Carbon Dioxidein a PMMA Compound

Abstract

Abstract Decompression experiments from a PMMA compound saturated with CO 2 at high pressure were performed to investigate the heterogeneous effect due to the aggregate of the additives on the microcellular foam structure generated. The observed results were compared with calculation results from a previously proposed homogeneous nucleation model. Uniform distribution of foams was obtained at a lower temperature of 20°C at various initial pressures tested. However, the heterogeneous effect due to the aggregate of the additives in the compound occurred at the solution temperature of 40°C, which is quite different from the results obtained in PMMA/CO 2 solution where homogeneous nucleation occurs in the temperature range between 40°C and 70°C. Experimental results obtained in this study may be applied to the injection-molding process of PMMA compounds.