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Phase Equilibria And Phase Separation Dynamics In A Polymer Composite Containing A Main-Chain Liquid Crystalline Polymer, Do Kim, Thein Kyu, Takeji Hashimoto
Phase Equilibria And Phase Separation Dynamics In A Polymer Composite Containing A Main-Chain Liquid Crystalline Polymer, Do Kim, Thein Kyu, Takeji Hashimoto
Thein Kyu
Various topological phase diagrams of blends of main-chain liquid crystalline polymer (MCLCP) and flexible polymer have been established theoretically in the framework of Matsuyama–Kato theory by combining Flory–Huggins (FH) free energy for isotropic mixing, Maier–Saupe (MS) free energy for nematic ordering in the constituent MCLCP, and free energy pertaining to polymer chain-rigidity. As a scouting study, various phase diagrams of binary flexible polymer blends have been solved self-consistently that reveal a combined lower critical solution temperature (LCST) and upper critical solution temperature (UCST), including an hourglass phase diagram. The calculated phase diagrams exhibit liquidus and solidus lines along with a …
Morphology Development In Polymer Fibers Undergoing Solvent/Non-Solvent Exchange, Pratyush Dayal, Thein Kyu
Morphology Development In Polymer Fibers Undergoing Solvent/Non-Solvent Exchange, Pratyush Dayal, Thein Kyu
Thein Kyu
The solvent/non-solvent interchange across the fiber surface affects the morphology of the fiber in various ways. In this paper, simulations have been performed to elucidate the diverse morphologies obtained during spinning of polymer fibers under the presence of a non-solvent. The proposed model deals with a ternary system derived from Cahn-Hilliard equation, alternatively known as Time Dependent Ginzburg Landau-TDGL model B equation, involving the spatio-temporal evolution of concentration order parameter. Depending on the coexistence region of the ternary phase diagram, various fiber morphologies including concentric bands, internal microfibrillar structures, and porous structures were discerned. It may be inferred that the …