Abstracts Engineering

Computational simulation and morphological analysis of polymerization-induced phase separation

by Junsuk. Oh

The phase separation method is a practically important method for producing multicomponent materials. Particularly, many commercialized polymer blends, such as High-Impact Polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS), are manufactured by the polymerization-induced phase separation (PIPS) method, polymerizing monomer compounds (styrene) in the presence of polymers (polybutadiene). In this thesis, rigorous mathematical models, describing the PIPS process, have been formulated using the nonlinear Cahn-Hilliard (C-H) theory and the Flory-Huggins (F-H) theory combined with a second-order reaction equation. In particular, this thesis analyzes and simulates for the first time the PIPS process for the case of a monomer polymerizing in the presence of a polymer. The model equations are solved using the numerical methods, and the simulation results are characterized to identify the main dynamical and morphological phenomena of the PIPS process. Lastly, the PIPS process under a temperature gradient is studied to produce functional composite materials exhibiting space-dependent microstructures and properties.