Investigation of domain structures in monomethoxy poly(ethylene glycol)-b-poly(caprolactone) grafted poly(acrylic acid) by NMR diffusion studies

TitleInvestigation of domain structures in monomethoxy poly(ethylene glycol)-b-poly(caprolactone) grafted poly(acrylic acid) by NMR diffusion studies
Publication TypeJournal Article
Year of Publication2022
AuthorsTiwari, N, Badiger, MVirupax, Rajamohanan, PRamanpilla, Ravindranathan, S
JournalPolymer International
Volume71
Issue8
Pagination976-984
Date PublishedAUG
Type of ArticleArticle
ISSN0959-8103
Keywordsassociating polymers, hydrophobically modified polymers, NMR diffusion studies, Rheology, sol-gel transition, thermoresponsive polymers
Abstract

Associating polymers developed by grafting a block copolymer of monomethoxy poly(ethylene glycol)-b-poly(caprolactone) (MPEG-b-PCL) onto poly(acrylic acid) undergo an irreversible sol-gel transition on heating. The influence of various physicochemical parameters on the thermoresponsive behaviour was examined by rheology and NMR studies. Pulsed field gradient NMR diffusion studies were performed to probe the mechanism of thermally induced gelation. Analysis of the diffusion data reveals the presence of loosely and strongly associated structures which respond differently to variation in temperature. It is observed that the polymer solution, which is visibly homogeneous, is heterogeneous on a mesoscopic scale with a distribution of domains. Detailed investigation of the thermally induced sol-gel transition shows that the mechanism of gelation involves irreversible alterations in the domain structure and size. (c) 2022 Society of Industrial Chemistry.

DOI10.1002/pi.6380
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

3.213

Divison category: 
Central NMR Facility
Polymer Science & Engineering
Database: 
Web of Science (WoS)

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