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Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System

The phase state diagram of the poly(vinyl methyl ether)-water system in a wide concentration range was obtained by the optical interferometry method. It was shown that this system was characterized by a complicated phase equilibrium with two lower critical solution temperatures, one of which was loc...

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Autores principales: Nikulova, Uliana V., Chalykh, Anatoly E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690603/
https://www.ncbi.nlm.nih.gov/pubmed/33105811
http://dx.doi.org/10.3390/polym12112445
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author Nikulova, Uliana V.
Chalykh, Anatoly E.
author_facet Nikulova, Uliana V.
Chalykh, Anatoly E.
author_sort Nikulova, Uliana V.
collection PubMed
description The phase state diagram of the poly(vinyl methyl ether)-water system in a wide concentration range was obtained by the optical interferometry method. It was shown that this system was characterized by a complicated phase equilibrium with two lower critical solution temperatures, one of which was located in the concentrated region at 21 °C, and the other one in the region of a dilute solution at 31 °C. In the framework of the Flory–Huggins theory, pair interaction parameters were calculated for different parts of the binodal curves, and an attempt was made to reverse simulate the diagram in different conditions. It was suggested that the unusual character of the diagram was associated with the formation of a complicated complex between PVME and water in the middle region of the compositions. Concentration profiles for different temperatures were constructed. For the first time for this system, the numerical values of the diffusion coefficients of poly(vinyl methyl ether) (PVME) into water and water in PVME were obtained. Concentration and temperature dependences of diffusion coefficients were constructed and analyzed. The kinetics of water sorption in PVME was plotted, the clustering integral was calculated, and the approximate number of molecules in a water cluster was estimated. It was shown that in the dilute solution region upon passing through the binodal curve, the interphase disappeared immediately, and the remaining fluctuation of the concentration decreased in size with time. The kinetics of this process was estimated from the change in the size of such a particle.
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spelling pubmed-76906032020-11-27 Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System Nikulova, Uliana V. Chalykh, Anatoly E. Polymers (Basel) Article The phase state diagram of the poly(vinyl methyl ether)-water system in a wide concentration range was obtained by the optical interferometry method. It was shown that this system was characterized by a complicated phase equilibrium with two lower critical solution temperatures, one of which was located in the concentrated region at 21 °C, and the other one in the region of a dilute solution at 31 °C. In the framework of the Flory–Huggins theory, pair interaction parameters were calculated for different parts of the binodal curves, and an attempt was made to reverse simulate the diagram in different conditions. It was suggested that the unusual character of the diagram was associated with the formation of a complicated complex between PVME and water in the middle region of the compositions. Concentration profiles for different temperatures were constructed. For the first time for this system, the numerical values of the diffusion coefficients of poly(vinyl methyl ether) (PVME) into water and water in PVME were obtained. Concentration and temperature dependences of diffusion coefficients were constructed and analyzed. The kinetics of water sorption in PVME was plotted, the clustering integral was calculated, and the approximate number of molecules in a water cluster was estimated. It was shown that in the dilute solution region upon passing through the binodal curve, the interphase disappeared immediately, and the remaining fluctuation of the concentration decreased in size with time. The kinetics of this process was estimated from the change in the size of such a particle. MDPI 2020-10-22 /pmc/articles/PMC7690603/ /pubmed/33105811 http://dx.doi.org/10.3390/polym12112445 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Nikulova, Uliana V.
Chalykh, Anatoly E.
Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System
title Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System
title_full Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System
title_fullStr Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System
title_full_unstemmed Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System
title_short Phase Equilibrium and Interdiffusion in Poly(Vinyl Methyl Ether)-Water System
title_sort phase equilibrium and interdiffusion in poly(vinyl methyl ether)-water system
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690603/
https://www.ncbi.nlm.nih.gov/pubmed/33105811
http://dx.doi.org/10.3390/polym12112445
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