Title
Synthesis and characterization of new pH- and thermo-responsive hydrogels based on N-isopropylacrylamide and 2-oxazolines
Date Issued
03 April 2014
Access level
open access
Resource Type
journal article
Author(s)
RUEDA SANCHEZ, JUAN CARLOS
Campos E.
Komber H.
Zschoche S.
Häussler L.
Voit B.
Publisher(s)
Taylor & Francis
Abstract
New pH- and thermo-responsive hydrogels (HG) were synthesized by free radical polymerization of N-isopropylacrylamide and a macromonomer, which was a hydrolyzed random copolymer of 2-carboxyethyl- and 2-methyl-2-oxazoline, using a bisacrylamide as crosslinker. The polymerization was carried out in a mixture of water and ethanol at room temperature and was initiated by ammonium peroxodisulfate. The HG showed conformational transitions with variation of temperature and/or pH-value and as a function of hydrogel composition. This property was shown macroscopically as hydrogel contraction or expansion. The HG structures were characterized by high-resolution magic angle spinning (HRMAS) NMR spectroscopy. The thermal properties, in particular the lower critical solution temperatures, were determined by temperature-dependent HRMAS NMR measurements and differential scanning calorimetry. The pH responsibility was determined by swelling experiments in water at different pH values. © 2013 Taylor & Francis.
Start page
208
End page
216
Volume
17
Issue
3
Language
English
OCDE Knowledge area
Química Ingeniería química
Publication version
Version of Record
Scopus EID
2-s2.0-84887475122
Source
Designed Monomers and Polymers
ISSN of the container
1568-5551
Sponsor(s)
The authors wish to thank the Academic Department of Research (DGI) of Pontifical Catholic University of Peru for the financial support for this research. The assistance of Dr M Edelmann in the DSC studies and A Korwitz in NMR measurements is gratefully acknowledged.
Sources of information: Directorio de Producción Científica Scopus