Static scattering from multicomponent polymer and copolymer systems

Benoît, H.; Benmouna, M.; Wu, Wen Li

doi:10.1021/ma00207a045

Cited by 76 publications

(70 citation statements)

References 4 publications

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“…The coherent scattering profile from an A/B/A-C multicomponent blend is given by [53][54][55] where B is a column-vector describing the contrast and S(q) is the a Mw is the weight-averaged molecular weight (the number of repeat units for deuterated polymers are equivalent to that of their hydrogenated counterparts), PDI is the polydispersity index, PDI ) Mw/Mn, where Mn is the number-averaged molecular weight; F is the average density, and nD is the number of deuterium atoms per C4 repeat unit. …”

Section: Experimental Methodsmentioning

confidence: 99%

Microphase and Macrophase Separation in Multicomponent A/B/A−C Polymer Blends with Attractive and Repulsive Interactions

et al. 2006

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A balanced A-C diblock copolymer surfactant was used to organize mixtures of immiscible A and B homopolymers. The C block of the copolymer exhibits repulsive and attractive interactions with the A and B homopolymers, respectively, leading to rich phase behavior. Experimental results indicate the existence of a microphase-separated state at low temperatures, a homogeneous phase at intermediate temperatures, and macrophase separation at high temperatures. It is unusual for a microphase-separated blend to exhibit a homogeneous phase prior to macrophase separation. In this study, component A was saturated polybutadiene with 89% 1,2-addition, component B was polyisobutylene, block A of the diblock copolymer was chemically equivalent to component A, and block C of the diblock copolymer was saturated polybutadiene with 63% 1,2-addition. We use a combination of Flory-Huggins theory (FHT), self-consistent field theory (SCFT) and the random-phase approximation (RPA) to understand the origin of our observations. All of the parameters needed for the SCFT, FHT, and RPA calculations were obtained from independent measurements. The measured length scale of the periodic concentration fluctuations in the homogeneous state and the domain spacing of the microphase-separated blends were in close agreement with RPA and SCFT, respectively. The transition temperatures between phases predicted with theory were in reasonable agreement with the experimental measurements.

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Section: Experimental Methodsmentioning

confidence: 99%

Microphase and Macrophase Separation in Multicomponent A/B/A−C Polymer Blends with Attractive and Repulsive Interactions

et al. 2006

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“…Given a compressible system of solvent and solute, one would like to determine the corresponding Γ -matrix. Detailed calculations exist for the incompressible case [15], which one can write:…”

Section: B) Compressible Systemsmentioning

confidence: 99%

A new approach to the problem of radiation scattering by multicomponent systems

Benoît

Jannink

2000

The European Physical Journal E

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The formulation of the scattered intensity by compressible systems, based on the thermodynamics of the inverse correlation matrix, is re-examined and replaced by a direct decomposition of the correlation matrix. This approach confirms known results. It allows the derivation of several families of contrasts and offers new possibilities to interpret scattering experiments. It can be easily generalized, in the frame of the random phase approximation, to the scattering at q = 0. PACS. 82.60.Lf Thermodynamics of solutions -42.25.Fx Diffraction and scattering -83.80.Es Polymer blends

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“…An excellent example for the thermodynamic approach is given by Ben-Naim (27) who used partial molar volumes, isothermal compressibilities, and partial vapor pressures to obtain Gij/Vj values in the waterethanol system. Scattering experiments were employed by Benoit et al, for example, to study concentration fluctuations in polymer solutions and polymer blends (28).…”

Section: Methodsmentioning

confidence: 99%

Solvent clustering, polar network density, and thermodynamic interactions in coordination polymers: an inverse gas chromatography study of metal-ion-containing polyesters of poly(diethylene glycol-co-succinic acid)

Vancso¹,

Tan²

1995

Can. J. Chem.

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Abstract:The spatial distribution of toluene and THF in the polyester poly(diethy1ene glycol-cosuccinic acid) and its Mg2+-containing "telechelic" derivative was described by Kirkwood-Buff-Zimm (KBZ) cluster integrals. The values of KBZ integrals as a function of the volume fraction of solvent in the polymer-solvent systems were obtained from finite concentration inverse gas chromatography measurements utilizing the elution-on-a-plateau technique. The results show that toluene has a higher self-affinity to form clusters in the pure polyester than THF, which is more homogeneously distributed in the polymer. Data for preferential solvation indicate that a segregation of parts of the polymer chains is present in the toluene-polyester system. When metal ions are introduced, the self-affinity of the solvent molecules to gather increases, whereas solvent clusters of toluene form in the free volume, and the gathering of the THF is likely to take place close to the metal ions. Based on the electron donacity values of the various donor groups present in the metal-ion-containing polymer it was assumed that THF in the Mg2+-containing polyester will be bound to the central metal ion while the apolar toluene will participate in the solvation of the apolar parts of the polymer and will be "repelled from the ion-containing regions. The concentration of these ionic centres, which act as effective cross-links in the coordination polymer, was determined from measurements of thermodynamic activity. A comparison of the experimental and estimated effective cross-link density values indicates a nearly atomic dispersion of Mg2+ in the metal-ioncontaining polyesters.Key words: inverse gas chromatography, cluster integrals, solvent partition in polymers, metal-ioncontaining polyesters, Flory-Huggins interaction parameter.RCsumC : Utilisant les intCgrales d7agrCgats de Kirkwood-Buff-Zimm (KBZ), on a dCcrit la distribution spatiale du tolubne et du THF dans le polyester, poly(di6thylbne glycol-co-acid succinique), et dans son dCrivC xttlCch6liqueu contenant du Mg2+. Utilisant la technique d'Clution sur un plateau lors de mesures de chromatographie en phase gazeuse inversCe, i concentration dCfinie, on a obtenu les valeurs des intigrales de KBZ en fonction de la fraction volumique du solvant dans les systbmes polymbre-solvant. Les rCsultats montrent que le tolubne possbde une autoaffinitk B former des agrCgats qui est plus grande dans le polyester pur que celle du THF qui est distribuC d'une faqon plus homogbne dans le polymkre.Les donntes relatives i la solvatation prCfCrentielle indiquent qu'il existe une sCgrCgation de parties des chaines de polymbre dans le systbme to~ubne-polyester. Quand on introduit des ions metalliques, l'autoaffinti des molCcules de solvant augmente, alors que les agrigats de solvant du tolubne se foment dans le volume libre, et I'agrtgation du THF se produit probablement prbs des ion mCtalliques. Sur la base des valuers exprimant la facilitC B donner des Clectrons des divers groupes donneurs prCsents dans le poly...

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Static scattering from multicomponent polymer and copolymer systems

Cited by 76 publications

References 4 publications

Microphase and Macrophase Separation in Multicomponent A/B/A−C Polymer Blends with Attractive and Repulsive Interactions

Microphase and Macrophase Separation in Multicomponent A/B/A−C Polymer Blends with Attractive and Repulsive Interactions

A new approach to the problem of radiation scattering by multicomponent systems

Solvent clustering, polar network density, and thermodynamic interactions in coordination polymers: an inverse gas chromatography study of metal-ion-containing polyesters of poly(diethylene glycol-co-succinic acid)

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