[en] Diblock copolymers poly(tetrahydrofuran-b-tert-butyl acrylate) (PTHF-b-PtBA) and poly(tetrahydrofuranb- 1-ethoxyethyl acrylate) (PTHF-b-PEEA) were successfully synthesized by the dual initiator 4-hydroxybutyl-2- bromoisobutyrate (HBBIB). The isobutyrate and alcohol function of HBBIB were used for the atom transfer radical polymerization of tBA ( or EEA) and the living cationic ring-opening polymerization of THF, respectively. Hydrolysis or thermolysis of the aforementioned diblock copolymers results in amphiphilic pH-responsive copolymers PTHF-b-poly( acrylic acid) ( PTHF-b-PAA). Matrix-assisted laser desorption/ ionization time-of-flight (MALDI-TOF) and nuclear magnetic resonance spectroscopy (H-1 NMR) were used to analyze the PTHF macroinitiator, while clear evidence for the formation of well-defined block copolymer structures was obtained by 1H NMR, gel permeation chromatography (GPC), and infrared spectroscopy (FT-IR). The amorphous PtBA block in PTHF-b-PtBA resulted in a decrease of the crystallinity and the melting point of PTHF, as shown by differential scanning calorimetry (DSC). Self-assembly of PTHF-b-PAA copolymers in water into aggregates and micelles when exposed to specific pH values was confirmed by dynamic light scattering, infrared, and NMR spectroscopies.
Research Center/Unit :
Center for Education and Research on Macromolecules (CERM)
Disciplines :
Chemistry Materials science & engineering
Author, co-author :
Bernaerts, Katrien V.; University of Ghent > Department of Organic Chemistry > Polymer Chemistry Research Group
Willet, Nicolas ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Van Camp, Wim; University of Ghent > Department of Organic Chemistry > Polymer Chemistry Research Group
Jérôme, Robert ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Du Prez, Filip E.; University of Ghent > Department of Organic Chemistry > Polymer Chemistry Research Group
Language :
English
Title :
pH-Responsive diblock copolymers prepared by the dual initiator strategy
Publication date :
30 May 2006
Journal title :
Macromolecules
ISSN :
0024-9297
eISSN :
1520-5835
Publisher :
Amer Chemical Soc, Washington, United States - Washington
FWO - Fonds Wetenschappelijk Onderzoek Vlaanderen [BE] BELSPO - Service Public Fédéral de Programmation Politique scientifique [BE] IWT - Agency for Innovation by Science and Technology [BE]
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