Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains

A new polycondensation aromatic rigid-chain polyester macroinitiator was synthesized and used to graft linear poly-2-ethyl-2-oxazoline as well as poly-2-isopropyl-2-oxazoline by cationic polymerization. The prepared copolymers and the macroinitiator were characterized by NMR, GPC, AFM, turbidimetry,...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Elena Tarabukina, Emil Fatullaev, Anna Krasova, Maria Sokolova, Mikhail Kurlykin, Igor Neelov, Andrey Tenkovtsev, Alexander Filippov
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	synthesis molecular brushes poly-2-alkyl-2-oxazolines solutions structural and conformation characteristics thermoresponsiveness Biology (General) QH301-705.5 Chemistry QD1-999
Acceso en línea:	https://doaj.org/article/5941b8b800494c60a25c59207b631f39
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:5941b8b800494c60a25c59207b631f39
record_format	dspace
spelling	oai:doaj.org-article:5941b8b800494c60a25c59207b631f392021-11-25T17:54:48ZThermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains10.3390/ijms2222122651422-00671661-6596https://doaj.org/article/5941b8b800494c60a25c59207b631f392021-11-01T00:00:00Zhttps://www.mdpi.com/1422-0067/22/22/12265https://doaj.org/toc/1661-6596https://doaj.org/toc/1422-0067A new polycondensation aromatic rigid-chain polyester macroinitiator was synthesized and used to graft linear poly-2-ethyl-2-oxazoline as well as poly-2-isopropyl-2-oxazoline by cationic polymerization. The prepared copolymers and the macroinitiator were characterized by NMR, GPC, AFM, turbidimetry, static, and dynamic light scattering. The molar masses of the polyester main chain and the grafted copolymers with poly-2-ethyl-2-oxazoline and poly-2-isopropyl-2-oxazoline side chains were 26,500, 208,000, and 67,900, respectively. The molar masses of the side chains of poly-2-ethyl-2-oxazoline and poly-2-isopropyl-2-oxazoline and their grafting densities were 7400 and 3400 and 0.53 and 0.27, respectively. In chloroform, the copolymers conformation can be considered as a cylinder wormlike chain, the diameter of which depends on the side chain length. In water at low temperatures, the macromolecules of the poly-2-ethyl-2-oxazoline copolymer assume a wormlike conformation because their backbones are well shielded by side chains, whereas the copolymer with short side chains and low grafting density strongly aggregates, which was visualized by AFM. The phase separation temperatures of the copolymers were lower than those of linear analogs of the side chains and decreased with the concentration for both samples. The LCST were estimated to be around 45 °C for the poly-2-ethyl-2-oxazoline graft copolymer, and below 20 °C for the poly-2-isopropyl-2-oxazoline graft copolymer.Elena TarabukinaEmil FatullaevAnna KrasovaMaria SokolovaMikhail KurlykinIgor NeelovAndrey TenkovtsevAlexander FilippovMDPI AGarticlesynthesismolecular brushespoly-2-alkyl-2-oxazolinessolutionsstructural and conformation characteristicsthermoresponsivenessBiology (General)QH301-705.5ChemistryQD1-999ENInternational Journal of Molecular Sciences, Vol 22, Iss 12265, p 12265 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	synthesis molecular brushes poly-2-alkyl-2-oxazolines solutions structural and conformation characteristics thermoresponsiveness Biology (General) QH301-705.5 Chemistry QD1-999
spellingShingle	synthesis molecular brushes poly-2-alkyl-2-oxazolines solutions structural and conformation characteristics thermoresponsiveness Biology (General) QH301-705.5 Chemistry QD1-999 Elena Tarabukina Emil Fatullaev Anna Krasova Maria Sokolova Mikhail Kurlykin Igor Neelov Andrey Tenkovtsev Alexander Filippov Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains
description	A new polycondensation aromatic rigid-chain polyester macroinitiator was synthesized and used to graft linear poly-2-ethyl-2-oxazoline as well as poly-2-isopropyl-2-oxazoline by cationic polymerization. The prepared copolymers and the macroinitiator were characterized by NMR, GPC, AFM, turbidimetry, static, and dynamic light scattering. The molar masses of the polyester main chain and the grafted copolymers with poly-2-ethyl-2-oxazoline and poly-2-isopropyl-2-oxazoline side chains were 26,500, 208,000, and 67,900, respectively. The molar masses of the side chains of poly-2-ethyl-2-oxazoline and poly-2-isopropyl-2-oxazoline and their grafting densities were 7400 and 3400 and 0.53 and 0.27, respectively. In chloroform, the copolymers conformation can be considered as a cylinder wormlike chain, the diameter of which depends on the side chain length. In water at low temperatures, the macromolecules of the poly-2-ethyl-2-oxazoline copolymer assume a wormlike conformation because their backbones are well shielded by side chains, whereas the copolymer with short side chains and low grafting density strongly aggregates, which was visualized by AFM. The phase separation temperatures of the copolymers were lower than those of linear analogs of the side chains and decreased with the concentration for both samples. The LCST were estimated to be around 45 °C for the poly-2-ethyl-2-oxazoline graft copolymer, and below 20 °C for the poly-2-isopropyl-2-oxazoline graft copolymer.
format	article
author	Elena Tarabukina Emil Fatullaev Anna Krasova Maria Sokolova Mikhail Kurlykin Igor Neelov Andrey Tenkovtsev Alexander Filippov
author_facet	Elena Tarabukina Emil Fatullaev Anna Krasova Maria Sokolova Mikhail Kurlykin Igor Neelov Andrey Tenkovtsev Alexander Filippov
author_sort	Elena Tarabukina
title	Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains
title_short	Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains
title_full	Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains
title_fullStr	Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains
title_full_unstemmed	Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains
title_sort	thermoresponsive molecular brushes with a rigid-chain aromatic polyester backbone and poly-2-alkyl-2-oxazoline side chains
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/5941b8b800494c60a25c59207b631f39
work_keys_str_mv	AT elenatarabukina thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT emilfatullaev thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT annakrasova thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT mariasokolova thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT mikhailkurlykin thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT igorneelov thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT andreytenkovtsev thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains AT alexanderfilippov thermoresponsivemolecularbrusheswitharigidchainaromaticpolyesterbackboneandpoly2alkyl2oxazolinesidechains
_version_	1718411861848752128

Thermoresponsive Molecular Brushes with a Rigid-Chain Aromatic Polyester Backbone and Poly-2-alkyl-2-oxazoline Side Chains

Ejemplares similares