Thermoresponsive poly(2-oxazoline) homopolymers and copolymers in aqueous solutions studied by NMR spectroscopy and dynamic light scattering

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F18%3A00488298" target="_blank" >RIV/61389013:_____/18:00488298 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1016/j.eurpolymj.2018.01.019" target="_blank" >http://dx.doi.org/10.1016/j.eurpolymj.2018.01.019</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.eurpolymj.2018.01.019" target="_blank" >10.1016/j.eurpolymj.2018.01.019</a>

Result language
angličtina
Original language name
Thermoresponsive poly(2-oxazoline) homopolymers and copolymers in aqueous solutions studied by NMR spectroscopy and dynamic light scattering
Original language description
Structural changes during temperature-induced phase transition in D2O solutions of poly(2-ethyl-2-oxazoline) (PEOx) and P(EOx-grad-2-methyl-2-oxazoline (MOx)) copolymers were investigated by 1H NMR methods in combination with dynamic light scattering. NMR spectra showed that in PEOx solutions on molecular level structures formed during gradual heating are preserved during subsequent cooling. Phase transition in solutions of P(EOx-grad-MOx) copolymers as revealed by NMR exists irrespective the solution is turbid or nonturbid at higher temperatures. In contrast to PEOx homopolymers it is very broad, virtually independent of the copolymer composition and molecular weight, and reversible with some hysteresis. Reduced intensities of cross-peaks in NOESY spectra of copolymer solutions at elevated temperatures are mainly due to the changed mobility of copolymer segments. In all investigated solutions two types of water, “free” and “bound” with long and very short spin–spin relaxation times T2, respectively, were detected in the transition region and above the transition. The existence of two T2 components shows that exchange between “bound” and “free” water is slow regarding T2 values.
Czech name
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Czech description
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Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10404 - Polymer science

Project
<a href="/en/project/GA15-13853S" target="_blank" >GA15-13853S: Structures and interactions in aqueous solutions of thermoresponsive polymers of a new type</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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