Hyperbranched Polymers in a Supercritical Fluid: Recent Progress on Phase Behavior and Modeling

Abstract: The advent of new chemistries has led to the creation of well-defined, novel polymer architectures. Due to their unique structures, hyperbranched polymers are receiving more and more attention and widely applied in various fields in the past two decades. In spite of their increasingly mature applications, some fundamental properties of star polymers are still lacking, such as their solubility behavior in different solvents, especially at high pressures. On the other hand, supercritical fluids (SCF) are ideal environmentally preferable solvents for polymer processing. This article intends to review the recent progress on the experimental determination and modeling of phase behavior of hyperbranched polymer systems, especially hyperbranched polymers in SCF. Following a brief description of the definition, properties, and applications of hyperbranched polymers, a detailed overview will be presented on the recent studies on phase behavior of hyperbranched polymer systems. Emphasis will be laid on the high-pressure phase behavior of polymers in SCF. Different models proposed by previous researchers will be then compared for the purpose of accurately predicting the phase equilibrium data. Finally current challenges will be discussed for future work