Polymer solution phase behavior modeling by chain-of-rotators equation of state
Abstract
Properties of saturated fluid states are used as basis to find the chain-of-rotators equation of state parameters for small polar molecules. Molecular contribution concept as well as innovative computer search procedures have been employed. Both moderately polar and strongly polar (hydrogen bonding) chemicals including acetates, alcohols, ketones, ethers, chlorinated organics, water, ammonia are evaluated and compared with experimental data. Chain-of-rotators equation of state is extended to describe fluid phase equilibria in polymer solutions by introducing mixing rules into the equation. New mixing rules obtained from excess Gibbs free energy models are investigated with the view of describing polymer solution phase behaviors for systems of polar solvents plus polymers or non-polar solvents plus polymers. Vapor-liquid equilibria are calculated in natural rubber - solvent, poly(dimethylsiloxane) - solvent, polyethylene - solvent, poly(ethylene glycol) - solvent, poly(ethylene oxide) - solvent, polyisobutylene - solvent, polyisoprene - solvent, polypropylene - solvent, poly(propylene glycol) - solvent, polystyrene - solvent, poly(vinyl acetate) - solvent, and poly(vinyl chloride) - solvent. With only two parameters from the modified Wilson model, each mixture system can completely be described by the chain-of-rotators equation of state at various temperatures. Results are shown and compared with several recently developed models. With the binary interaction parameter cubic (BIP3) mixing rules, the chain-of-rotators equation of state is further applied to various binary polymer mixtures or blends to study the compatibility of polymer systems. Systems of polystyrene - poly(vinyl methyl ether), poly(vinyl methyl ether) - phenoxy, polycarbonate - poly(methyl methacrylate), and polysulfone - poly(ethylene oxide) are studied. Cloud-point curves have been correlated for such systems. Specific polymer-polymer interaction is favorable in the formation of compatible blends. Methods of predicting the compatibility of polymer systems are presented.
Degree
Ph.D.
Advisors
Chao, Purdue University.
Subject Area
Chemical engineering|Plastics
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