Interpolymer Complex between Hydroxypropyl Cellulose and Maleic Acid–Styrene Copolymer: Phase Behavior of Semi‐Dilute Solutions

Bumbu, Gina-Gabriela; Eckelt, John; Wolf, Bernhard; Vasile, Cornelia

doi:10.1002/mabi.200500070

Cited by 8 publications

(5 citation statements)

References 40 publications

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“…40-45°C. It decreases with M w and concentration of HPC (Lu et al 2002), and also drastically reduces to even single digit upon the formation of complexes such as HPC/poly(acrylic acid) (Lu et al 2002), HPC/methacrylic acid (MAA) (Liao et al 2012), and HPC/maleic acid-styrene copolymer (Bumbu et al 2005). With respect to the effect of DS, Zhang et al reported that the sol-gel transition temperature (T gel ) of hydroxypropyl chitin could be tuned from *20 to *80°C with decreasing DS from 1.29 to 0.25 .…”

Section: Introductionmentioning

confidence: 98%

Thermal inverse phase transition of azobenzene hydroxypropylcellulose in aqueous solutions

Zhang

Liu

2016

Cellulose

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Water soluble 2-azobenzenoxy-ethoxyhydroxpropylcelluloses (azo-EHPC) were synthesized by etherification reaction of bromoethoxy-azobenzene (BEA) with hydroxypropylcellulose (HPC) to study their phase transition behavior in aq. solution. The degree of substitution (DS) of the water soluble azoEHPCs was less than 0.066. Their chemical structure and thermal property were characterized by proton nuclear magnetic resonance ( 1 H-NMR), fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry. The azo-EHPC showed a reversible sol-gel transition behavior in its aq. solution, i.e. a clear azo-EHPC aq. solution became turbid when the solution temperature surpassed a lower critical solution temperature (LCST). The sol-gel transition phenomenon was investigated by optical microscopy and turbidimetric measurement. It was found that the LCST was related to the cis-/transconformation of the azobenzene side group, the type of cyclodextrin (CD), concentration of azo-EHPC, and NaCl concentration. The LCST of azo-EHPC was lower than that of HPC (36.6°C) by at most 13.6°C, and the LCST of trans-azo-EHPC was less than that of cis-azo-EHPC by ca. 3°C. Additionally, the presence of CD in solutions displayed a positive effect on the LCST, i.e. increasing the LCST by 3-5°C. And this impact was more profound on the azo-EHPC with higher DS values. The thermoreversible phase transition mechanism was discussed. We proposed that the effect of DS, conformation of azobenzene group, azo-EHPC concentration, salt concentration, and CD on the LCST of azo-EHPCs was a rearrangement of the hydrophilic/hydrophobic interaction between side azobenzene groups and water molecules.

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Section: Introductionmentioning

confidence: 98%

Thermal inverse phase transition of azobenzene hydroxypropylcellulose in aqueous solutions

Zhang

Liu

2016

Cellulose

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“…A balance of the overall free energy gives rise to the phase separation of the D and S phases at high temperature. Experimentally, a similar transition from a homogeneous phase to a liquid−liquid phase, each phase being solvated, is observed by increasing temperature, or the solubility between polymer and solvent. , Moreover, it is also observed that an increase in polymer concentration gives rise to the liquid−liquid phase separation. In Figure , such transitions are found as a coexistence of the D and S phases bounded by the homogeneous phases.…”

Section: Discussionmentioning

confidence: 81%

Phase Separation Induced by Ladder-Like Polymer−Polymer Complexation

Nakamura

Shi

2011

J. Phys. Chem. B

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Polymer-polymer complexation in solvent is studied using an extension of the self-consistent field theory. The model polymers are capable of forming ladder-like duplex structures. The duplex formation occurs with an abrupt change of entropy, resulting in a first-order transition. Moreover, the complexation can be stabilized by solvent-polymer interactions, instead of the usual specific binding interactions. Various types of unconventional phase diagrams are predicted. For example, phase separation with decreasing χ-parameter between duplex polymer and solvent can be induced, leading to a lower critical solution temperature (LCST) behavior. Multiphase coexistence points at which two, three, or four phases coexist are also obtained. Under certain conditions a homogeneous phase becomes unstable when the polymer chain length is decreased, in contrast to the standard Flory-Huggins theory.

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“…As shown in Figure , the cloud point of each mixed solution is lower than both cloud points of PVCL and PHPA. The lowest cloud point appears at a mole fraction of 0.17, which is related not only to stoichiometry but also to the fact that the molecular weight of PVCL is 5 times as high as that of PHPA. − The significant decrease of cloud point could be attributed to the formation of interpolymer complex via intermolecular forces. ,, …”

Section: Resultsmentioning

confidence: 96%

“…To find a pair of polymers suited for LbL assembly, we studied the change of cloud point of mixed solutions of every two temperature-responsive polymers and found that the cloud points of some mixed solutions significantly decreased. Because a decrease of cloud point suggested the formation of interpolymer complex via intermolecular forces in the mixed solutions, we selected PVCL and poly(2-hydroxypropyl acrylate) (PHPA) for LbL assembly. In the temperature range between the lower one of the cloud points of two polymer solutions and the cloud point of mixed solution, the solubility of the interpolymer complex is poor, which facilitates polymer adsorption on a solid surface.…”

Section: Introductionmentioning

confidence: 99%

Layer-by-Layer Assembly of Two Temperature-Responsive Homopolymers at Neutral pH and the Temperature-Dependent Solubility of the Multilayer Film

et al. 2012

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We fabricated a layer-by-layer (LbL) film of temperature-responsive homopolymers at neutral pH and studied its temperature-dependent solubility. We first measured the cloud point of mixed solutions of temperature-responsive polymers. The significant decrease of cloud point suggested that the intermolecular interaction between two polymer chains of different kinds was stronger than that between two polymer chains of the same kind. Strong intermolecular interaction between two polymer chains of different kinds is a prerequisite for LbL assembly. On the basis of the decrease of cloud point of mixed solutions of temperature-responsive homopolymers, we selected poly(N-vinylcaprolactam) (PVCL) and poly(2-hydroxypropyl acrylate) (PHPA) for LbL assembly. LbL films of the two polymers were fabricated at neutral pH at a constant temperature. When the film was immersed in purified water at a temperature lower than the assembly temperature, it can be partially dissolved with a diffusion-limited dissolution process. The temperature-responsive solubility of the LbL film is closely connected to the phase behavior of mixed solutions of the two polymers. Additionally, as compared to multilayer films of neutral polymers and poly(carboxylic acid)s, the PVCL/PHPA multilayer film is relatively stable when it was immersed in buffer solutions near physiological pH at the assembly temperature. Such LbL films with temperature-responsive solubility might be used as a dissolvable film or a smart capsule.

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Interpolymer Complex between Hydroxypropyl Cellulose and Maleic Acid–Styrene Copolymer: Phase Behavior of Semi‐Dilute Solutions

Cited by 8 publications

References 40 publications

Thermal inverse phase transition of azobenzene hydroxypropylcellulose in aqueous solutions

Thermal inverse phase transition of azobenzene hydroxypropylcellulose in aqueous solutions

Phase Separation Induced by Ladder-Like Polymer−Polymer Complexation

Layer-by-Layer Assembly of Two Temperature-Responsive Homopolymers at Neutral pH and the Temperature-Dependent Solubility of the Multilayer Film

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