Supercritical fluid assisted polymer blending

The melt viscosity of individual homopolymers is one of the most important parameters influencing polymer blending. Often times blending involves components with vastly different viscosities. Supercritical carbon dioxide can be added to polymer melts in order to lower their viscosities such that effective polymer blending will occur. A blend system of a high viscosity polymethylmethacrylate (PMMA) and low viscosity polystyrene, viscosity ratio of about twenty is analyzed in this work. Carbon dioxide has a higher affinity for PMMA than for polystyrene. Therefore the viscosity of the PMMA will be selectively lowered by the carbon dioxide such that it becomes closer to that of polystyrene. An improvement in polymer blending results and will be shown in this work.