Authors Rueda, J.C. ; Campos, E. ; Komber, H. ; Zschoche, St. ; Häußler, L. ; Voit, B.
Title Synthesis and characterization of new pH- and thermo-responsive hydrogels based on N-isopropylacrylamide and 2-oxazolines
Date 01.03.2014
Number 38203
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.
Publisher Designed Monomers and Polymers
Citation Designed Monomers and Polymers 17 (2014) 208-216
Tags hydrogels stimuli-sensitive polymers networks graft copolymers macromonomers swelling graft-copolymers poly(n-isopropylacrylamide) polymerization temperature

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