Application of lattice cluster theory to the calculation of miscibility-and interfacial behavior of hyperbranched polymer containing systems

Newly developed hyperbranched polymers possess a compact, highly branched, three-dimensional structure, which has a high density of functional end groups and inherently low viscosity. The combination of these two properties, low viscosity and high reactivity, makes them attractive candidates for an overwhelming variety of applications. The experimental and theoretical investigation of the phase behavior of hyperbranched polymer systems is a crucial requirement for a successful introduction of new applications to highly competitive markets. In this context, thermodynamic models, which accurately account for the impact of polymer branching on the phase behavior of polymer systems, play a very important role. The lattice cluster theory (LCT) is an extension of the well-known Flory-Huggins theory, especially in the calculation of the entropy of the lattice. Whereas the Flory-Huggins theory is limited to linear chains the LCT can be applied to arbitrary chain architecture. This situation permits the incorporation of the architecture in the thermodynamic functions useful for phase equilibrium calculations. The polymer architecture plays an important role in the physical properties of hyperbranched polymers. Additionally, the combination of the LCT with the density gradient theory allows the theoretical investigation of the interfacial properties between the demixed phases.