Phase diagram of mixtures of polymers in aqueous solution using Fourier-transform infrared spectroscopy

Durrani, C. Matin; Prystupa, D. A.; Donald, Athene M.; Clark, Allan H.

doi:10.1021/ma00057a016

Cited by 62 publications

(29 citation statements)

References 7 publications

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“…For systems where χ 1s =χ 2s , the tie lines are parallel 27 , unlike those in Figure 3, which are similar to the system of gelatin with higher molecular weight amylopectin 16 . The steeper tie line corresponding to the more concentrated ι-carrageenan/maltodextrin sample (Figure 3) suggests closer values of χ 1s and χ 2s at higher biopolymer concentration 27,31 .…”

Section: Discussionmentioning

confidence: 72%

“…In contrast to κ-carrageenan gels that are brittle and hard, ι-carrageenan can produce more flexible and soft gel textures that closely resemble gelatin gels. Depending on the concentration of polymer and type and concentration of cation, the gelation and melting temperatures of ι-carrageenan gels occur over a broader range and are generally higher (>50°C) 15 than for gelatin (~35°C) 16 . κ-Carrageenan shows ion-specific binding to the alkali salts such as potassium that can induce helix formation and gelation via interhelical bonding, whereas its interaction with, e.g., sodium is nonspecific and long-range.…”

Section: Introductionmentioning

confidence: 99%

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Phase Behavior of the ι-Carrageenan/Maltodextrin/Water System at Different Potassium Chloride Concentrations and Temperatures

Wang

Ziegler

2009

Food Biophysics

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Equilibrium phase diagrams of the ι-carrageenan/ maltodextrin/water system have been established at potassium chloride (KCl) concentrations of 0.1, 0.2, and 0.3 M and 80, 85 and 90°C. All pseudo-binary phase diagrams of ι-carrageenan/maltodextrin mixtures suggested classic segregative phase separation. The binodal was heavily skewed toward the maltodextrin axis. The high asymmetry of the ι-carrageenan/maltodextrin/water phase diagram determined by the phase-volume-ratio method was consistent with the compositional analysis of phase-separated ι-carrageenan/ maltodextrin samples and can be explained in terms of the Flory-Huggins interaction parameter, reflecting a higher water-binding ability of the charged ι-carrageenan than neutral maltodextrin. Increasing the concentration of ι-carrageenan-gel-promoting KCl from 0.1 to 0.3 M at 80°C enlarged the two-phase domain, whereas increasing temperature from 80 to 90°C at 0.3 M KCl enhanced biopolymer compatibility. The effects of salt concentration and temperature have been related to the differences in the Flory-Huggins interaction parameters of the two biopolymers with water as well as the helix formation of ι-carrageenan in the presence of KCl through the changes in the slopes of tie lines of phase-separated samples.

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Section: Discussionmentioning

confidence: 72%

Section: Introductionmentioning

confidence: 99%

Phase Behavior of the ι-Carrageenan/Maltodextrin/Water System at Different Potassium Chloride Concentrations and Temperatures

Wang

Ziegler

2009

Food Biophysics

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“…They reported that their micrographs appeared quite similar to those observed in a number of synthetic interpenetrating networks (referred to as IPNs) 110,111 , and showed phase separation into the two polymer networks with possible phase inversion at a certain mixture composition. Durrani et al 112,113 derived a phase diagram for the ternary amylopectin-gelatin-D 2 O mixture in the sol state by the use of Fourier transformed infrared microspectroscopy.…”

Section: Multicomponent Gelationmentioning

confidence: 99%

Theoretical Study of Molecular Association and Thermoreversible Gelation in Polymers

Tanaka

2002

Polym J

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ABSTRACT:This paper reviews our recent theoretical studies of molecular association and thermoreversible gelation in polymer solutions and blends. We first classify fundamental types of association, and propose their static and dynamic characterization. We then develope general theory of associating polymers to study phase transitions induced by molecular association. These transitions include macro-and microphase separation, micellization, hydration, thermoreversible gelation and liquid-crystalization. As for the origin of associative forces, we focus on hydrogen bonding and hydrophobic aggregation. Detailed study on thermoreversible gelation with multiple cross-link junctions is presented. Paying special attention to the multiplicity and sequence length of the network junctions, we derive phase diagrams with coexisting gelation and phase separation, and compare them with experimental data. Local and global structures of the gel networks are studied from molecular point of view. The theory is applied to more complex thermoreversible gels such as binary networks (interpenetrating networks, alternating networks and randomely mixed networks), hydrated networks with high-temperature gelation, gelation strongly coupled to polymer conformational transitions such as coil-to-helix transition. To study dynamics of thermoreversible gels, a simple transient network model is introduced, and creation and annihilation of junctions in the networks are theoretically described. Stationary non-linear viscosity and the dynamic mechanical moduli are calculated as functions of the shear rate, frequency and the chain disengagement rate. From the peak of the loss modulus, the lifetime τ × of the junction is estimated, and from the high frequency plateau of the storage modulus, the number of elastically effective chains in the network is found. Transient phenomena such as stress relaxation and stress overshoot are also theoretically studied. Results are compared with the recent experimental reports on the rheological study of hydrophobically modified water-soluble polymers.KEY WORDS Associating Polymers / Thermoreversible Gelation / Junction Multiplicity / Multicriticality / Transient Networks / Shear Thickening / Elastically Effective Chains / This paper reviews our recent theoretical studies of molecular association and thermoreversible gelation in polymer solutions. We introduce new theoretical frameworks to study phase transitions induced by association of polymer chains and dynamics of aggregation/dissociation processes.In most polymer blends or solutions, polymer chains carry active groups interacting with each other via strongly associative forces which are capable of forming temporal bonds. Hence description of the system in terms of van der Waals type contact energy -or χ-parameter in lattice theoretical terminology -is insufficient. These associative interactions include hydrogen bonding, ionic aggregation, electrostatic interaction, micro-crystallite formation, stereocomplex formation, solvent-complex formation, etc. Since ...

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“…The formation of the maltodextrin gel is strongly concentration and time dependent. 15 Maltodextrin is believed to form a gel of densely packed crystallite particles.…”

Section: Experimental Composite Fabricationmentioning

confidence: 99%

Large deformation mechanical behavior of gelatin–maltodextrin composite gels

Normand¹,

Plucknett²,

Pomfret³

et al. 2001

J of Applied Polymer Sci

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ABSTRACT:The large deformation failure behavior of gelatin-maltodextrin composite gels was assessed. All the studied compositions were selected to lie within the incompatibility domain of the gelatin-maltodextrin phase diagram at 60°C, which produced gelatin continuous (maltodextrin included) and maltodextrin continuous (gelatin included) composites. Composite microstructural evaluation was performed using confocal laser scanning microscopy (CLSM). The large deformation mechanical behavior was measured in tension and compression experiments. Crack-microstructure interactions were investigated by dynamic experiments on the CLSM. The gelatin continuous composites exhibited pseudo-yielding behavior during tension and compression testing, and there was a significant decrease in modulus that arose from interfacial debonding. Conversely, the maltodextrin continuous composites exhibited an essentially brittle failure behavior, and there was an approximately linear increase in stress with increasing strain until fracture (which occurred at significantly lower strains than for the gelatin continuous composites). The CLSM observation of the failure of the notched samples also demonstrated interfacial debonding in the crack path; however, this occurred at significantly smaller strains than for the gelatin continuous samples with minimal elastic-plastic deformation of the maltodextrin matrix. The Poisson ratio was estimated to be close to 0.5 for these composites for all examined compositions. Compositions corresponding to a tie line of the phase diagram were also investigated to assess the influence of the relative phase volume (for constant phase compositions) on the failure behavior. The majority of the parameters subsequently extracted from the stress-strain curves were apparently functions of the individual phase volumes.

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Phase diagram of mixtures of polymers in aqueous solution using Fourier-transform infrared spectroscopy

Cited by 62 publications

References 7 publications

Phase Behavior of the ι-Carrageenan/Maltodextrin/Water System at Different Potassium Chloride Concentrations and Temperatures

Phase Behavior of the ι-Carrageenan/Maltodextrin/Water System at Different Potassium Chloride Concentrations and Temperatures

Theoretical Study of Molecular Association and Thermoreversible Gelation in Polymers

Large deformation mechanical behavior of gelatin–maltodextrin composite gels

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