A novel pH-sensitive PEG-PPG-PEG copolymer displaying a closed-loop sol–gel–sol transition

Autor:	Je Kim Ju Eun Kim, Tg Park Tae Gwan Park, Sy Lee Seung Yong Lee, Ch Ahn Cheol-Hee Ahn, Yuhan Lee Lee
Rok vydání:	2009
Předmět:	End-group chemistry.chemical_compound Aqueous solution Chemistry Diamine Polymer chemistry Self-healing hydrogels PEG ratio Materials Chemistry Copolymer General Chemistry Dynamic mechanical analysis Poloxamer
Zdroj:	Journal of Materials Chemistry. 19:8198
ISSN:	1364-5501 0959-9428
Popis:	A thermogelling PEG-PPG-PEG triblock copolymer, Pluronic F127, was modified with diamines containing different numbers of secondary amino groups in order to produce a novel pH-sensitive gelling material. The degree of end group modification was over 95% without any noticeable multi-block formation. Modified F127 displayed a closed-loop sol–gel–sol transition in 16 wt% PBS solution and the loop was significantly shifted with pH depending on the nature of end-capping diamines. Temperature- and pH-sensitive phase transition was caused by a subtle change in hydrophilicity and hydrophobicity balance derived from the pKa values of the diamine groups at the distal PEG blocks. 1H-NMR, GPC and dynamic mechanical analysis were employed for the characterization of modified F127 and its gelation behavior.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fc1288af634dddf25fffc3c8f0118ce5 https://doi.org/10.1039/b912540j Zobrazit plný text záznamu