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Temperature and pH-Dependent Response of Poly(Acrylic Acid) and Poly(Acrylic Acid-co-Methyl Acrylate) in Highly Concentrated Potassium Chloride Aqueous Solutions

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Department of Chemical Engineering and Process Design, Faculty of Chemistry, Silesian University of Technology, 44-100 Gliwice, Poland
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Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, 44-100 Gliwice, Poland
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Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Hyogo 671-2280, Japan
*
Authors to whom correspondence should be addressed.
Polymers 2020, 12(2), 486; https://doi.org/10.3390/polym12020486
Received: 15 January 2020 / Revised: 13 February 2020 / Accepted: 17 February 2020 / Published: 21 February 2020
(This article belongs to the Section Polymer Processing and Engineering)
In this study, the phase transition phenomena of linear poly(acrylic acid) (PAA) and linear or star-shaped poly(acrylic acid-co-methyl acrylate) (P(AA-co-MA)) in highly concentrated KCl solutions were investigated. The effects of polymer molecular weight, topology, and composition on their phase transition behavior in solution were investigated. The cloud point temperature (TCP) of polymers drastically increased as the KCl concentration (CKCl) and solution pH increased. CKCl strongly influenced the temperature range at which the phase transition of PAA occurred: CKCl of 1.0–2.2 M allowed the phase transition to occur between 30 and 75 °C. Unfortunately, at CKCl above 2.6 M, the TCP of PAA was too high to theoretically trigger the crystallization of KCl. The addition of hydrophobic methyl acrylate moieties decreased the TCP into a temperature region where KCl crystallization could occur. Additionally, the hydrodynamic diameters (Dh) and zeta potentials of commercial PAA samples were examined at room temperature and at their TCP using dynamic light scattering. The salt concentration (from 1 to 3 M) did not impact the hydrodynamic diameter of the molecules. Dh values were 1500 and 15 nm at room temperature and at TCP, respectively. View Full-Text
Keywords: poly(acrylic acid); upper critical solution temperature (UCST); phase transition; star polymer; inorganic salt solutions; KCl poly(acrylic acid); upper critical solution temperature (UCST); phase transition; star polymer; inorganic salt solutions; KCl
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MDPI and ACS Style

Sinek, A.; Kupczak, M.; Mielańczyk, A.; Lemanowicz, M.; Yusa, S.-i.; Neugebauer, D.; Gierczycki, A. Temperature and pH-Dependent Response of Poly(Acrylic Acid) and Poly(Acrylic Acid-co-Methyl Acrylate) in Highly Concentrated Potassium Chloride Aqueous Solutions. Polymers 2020, 12, 486. https://doi.org/10.3390/polym12020486

AMA Style

Sinek A, Kupczak M, Mielańczyk A, Lemanowicz M, Yusa S-i, Neugebauer D, Gierczycki A. Temperature and pH-Dependent Response of Poly(Acrylic Acid) and Poly(Acrylic Acid-co-Methyl Acrylate) in Highly Concentrated Potassium Chloride Aqueous Solutions. Polymers. 2020; 12(2):486. https://doi.org/10.3390/polym12020486

Chicago/Turabian Style

Sinek, Aleksander, Maria Kupczak, Anna Mielańczyk, Marcin Lemanowicz, Shin-ichi Yusa, Dorota Neugebauer, and Andrzej Gierczycki. 2020. "Temperature and pH-Dependent Response of Poly(Acrylic Acid) and Poly(Acrylic Acid-co-Methyl Acrylate) in Highly Concentrated Potassium Chloride Aqueous Solutions" Polymers 12, no. 2: 486. https://doi.org/10.3390/polym12020486

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