Lower Critical Solution Temperature Behavior of Comb and Graft Shaped Poly[oligo(2-ethyl-2-oxazoline)methacrylate]s
-
Weber, Christine; Becer, C. Remzi; Hoogenboom, Richard; Schubert, Ulrich S.
- Abstract:
- Comb and graft polymers with lower critical solution temperature (LCST) behavior based on
hydrophilic oligo(2-ethyl-2-oxazoline) side chains and a hydrophobic methacrylate backbone were synthesized
using the macromonomer method. Well-defined oligo(2-ethyl-2-oxazoline) methacrylate (OEtOxMA) macromonomers
were obtained by direct end-capping of living oligo(2-ethyl-2-oxazoline) chains with in situ formed
triethylammonium methacrylate. The macromonomers were subsequently polymerized in a controlled manner
using the reversible addition-fragmentation chain transfer (RAFT) polymerization technique yielding a series of
comb polymers with varying side chain length and backbone length. In addition, a series of graft copolymers
were prepared by copolymerizing OEtOxMA with methyl methacrylate (MMA, 40-80 mol %). The copolymers
were characterized by 1H NMR spectroscopy, size exclusion chromatography (SEC), and, partially, by matrixassisted
laser desorption ionization (MALDI-TOF) mass spectrometry. The LCST behavior of aqueous polymer
solutions was investigated by turbidity measurements revealing cloud points that can be tuned from 35 to 80 °C
by variation of the MMA content.
- Year:
- 2009
- Type of Publication:
- Article
- Journal:
- Macromolecules
- Volume:
- 42
- Pages:
- 2965 - 2971