Miscibilities in binary copolymer systems

Hino, Toshiaki; Lambert, Stephen M.; Soane, David S.; Prausnitz, John M.

doi:10.1016/0032-3861(93)90714-l

Cited by 8 publications

(5 citation statements)

References 11 publications

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“…When ε AB < min[ε AA , ε BB ], like segments are attractive toward each other, but unlike segments are repulsive toward each other, mixture therefore will be non-randomness. This phenomenon is more notable if strong or oriented interactions from hydrogen bonding or other specific forces exist between segments as Hino et al [24] have discussed. On the other hand, the derivation of the R-F model doesn't consider non-randomness of mixing.…”

Section: Molecular Thermodynamics Modelmentioning

confidence: 89%

Molecular thermodynamics model for random copolymer solutions

Chen

Peng

Liu

et al. 2005

Fluid Phase Equilibria

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Similar to the work done by Kambour et al. and ten Brinke et al., an effective interchange energy parameter ε eff is introduced into the calculation of binodal curves for random copolymer systems according to the Revised Freed (R-F) model previously established by Hu et al. for homopolymer system. ε eff is a function of chain composition and various pairs of energy parameters. For contrast, the Flory-Huggins (F-H) model has also been extended to study random copolymer system in the similar way. In order to check the validity of this kind of approach, the calculated results have been compared with the corresponding MC simulation data. It is shown that the results obtained by R-F model are quite consistent with MC simulation data while that by F-H model shows large deviation due to the excess mean-field approximation employed.

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Section: Molecular Thermodynamics Modelmentioning

confidence: 89%

Molecular thermodynamics model for random copolymer solutions

Chen

Peng

Liu

et al. 2005

Fluid Phase Equilibria

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“…Based on the mean-field theory of Kambour et al, ten Brinke et al extended the model to random copolymer−copolymer systems and found that miscibility in these systems does not require any specific interaction but rather a “repulsion” between the different covalently bonded monomers of the copolymers. Hino et al developed a lattice theory for liquid−liquid equilibrium of binary systems containing random copolymers by taking into account deviations from random mixing through a nonrandomness factor. To overcome the problems brought by the mean-field theory, Freed developed a rigorous analytical solution of the F−H lattice.…”

Section: Introductionmentioning

confidence: 99%

Molecular Thermodynamic Model of Multicomponent Chainlike Fluid Mixtures Based on a Lattice Model

Xin

Peng

Liu

et al. 2008

Ind. Eng. Chem. Res.

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The molecular thermodynamic model of polymer solutions based on a close-packed lattice model presented in a previous work has been generally extended to multicomponent chainlike fluid mixtures. The Helmholtz function of mixing contains three terms, i.e., the contribution of athermal mixing of polymer chains, which is calculated by Guggenheim's theory; the contribution of nearest-neighbor interactions between monomers, which is calculated by Yang et al.'s model of the Helmholtz function of mixing for a multicomponent Ising lattice; and the contribution of the formation of polymer chains from monomers, which is obtained according to the sticky-point theory of Cummings, Zhou, and Stell. The liquid-liquid phase equilibria of ternary chainlike mixtures predicted by this model are in good agreement with Monte Carlo simulation results and superior to the results calculated by Flory-Huggins (FH) theory and revised Freed theory (RFT) obviously. This model not only can describe types 1-3 phase separations of Treybal classification satisfactorily, but can also correlate well the coexistence curves of binary polymer blends systems with an upper critical solution temperature (UCST) or a lower critical solution temperature (LCST). Meanwhile, model parameters correlated from the binary system can be further extended to predict the corresponding liquid-liquid equilibrium of ternary mixtures, including systems of ionic liquids.

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“…Similarly, is the minimum potential energy between dissimilar segments a and ß. An additional adjustable intersegmental parameter, ^, can also be introduced to relax the additivity of effective hard-sphere diameters of unlike segments a and /3:36,38 1/3 (bf + bl/s) C = ~¿ (1 " °ß) ( ^} (2) where ba and represent the van der Waals covolumes for effective hard spheres between similar and dissimilar segments, respectively; ba and ba¿ account for the excluded volume due to repulsive forces. The intersegmental parameters are obtained from experimental phase boundaries such as the critical point of the mixture and the boundary between miscible and immiscible regions on the miscibility map.…”

Section: Introductionmentioning

confidence: 99%

Equation-of-State Analysis of Binary Copolymer Systems. 2. Homopolymer and Copolymer Mixtures

Hino¹,

Song²,

Prausnitz³

1995

Macromolecules

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The perturbed hard-sphere-chain (PHSC) equation of state for copolymer systems is applied to binary homopolymer blends and to mixtures of homopolymer and copolymer. Theoretical results for the effect of copolymer composition on lower critical solution temperature (LCST) are compared with experiment for homopolymer/copolymer mixtures containing poly(methyyl methacrylate-co-styrene) (MMAco-S) and poly(acrylonitrile-co-styrene) (AN-co-S) random copolymers. The intersegmental parameters for the MMA-S and AN-S pairs are obtained from the miscibility maps containing MMA-co-S and ANco-S random copolymers, respectively, differing in copolymer compositions. The homopolymer/copolymer systems studied in this work exhibit LCSTs in the experimentally accessible temperature range as the copolymer approaches 100% polystyrene. The PHSC equation of state predicts that the LCST of a homopolymer/copolymer system exhibits a maximum as the copolymer composition varies. Unique values are assigned to the intersegmental parameters for a given pair of segments.

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Miscibilities in binary copolymer systems

Cited by 8 publications

References 11 publications

Molecular thermodynamics model for random copolymer solutions

Molecular thermodynamics model for random copolymer solutions

Molecular Thermodynamic Model of Multicomponent Chainlike Fluid Mixtures Based on a Lattice Model

Equation-of-State Analysis of Binary Copolymer Systems. 2. Homopolymer and Copolymer Mixtures

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