18 research outputs found
2-Isopropenyl-2-oxazoline : a versatile monomer for functionalization of polymers obtained via RAFT
2-Isopropenyl-2-oxazoline (iPOx) was polymerized for the first time via a controlled radical polymerization technique. Reversible addition–fragmentation chain transfer (RAFT) polymerization utilizing a dithiobenzoate-based chain transfer agent was employed to form a backbone that is highly reactive toward thiols and acids. Moreover, the statistical copolymerization of iPOx with methyl methacrylate (MMA) and N-iso-propylacrylamide (NiPAm) was investigated resulting in two copolymer series with iPOx content varying from 100% to 13% (PDI = 1.37 to 1.21). The P(iPOx-stat-NiPAm) copolymers displayed thermoresponsive behavior in water as well as phosphate buffered saline at higher temperatures in comparison to homopolymers of NiPAm due to the hydrophilicity of the introduced iPOx moieties (Tcp = 25 to 75 °C). Futhermore, iPOx-based (co)polymers were functionalized by polymer analogous addition reactions with thiophenol, benzoic acid and 4-azidobenzoic acid in high conversions (74–100%). The latter adduct represented a suitable building block for the synthesis of a graft copolymer consisting of a PMMA backbone and poly(2-ethyl-2-oxazoline) (PEtOx) side chains via copper-catalyzed azide–alkyne cycloaddition (CuAAC) of PEtOx with alkyne terminus
2-Isopropenyl-2-oxazoline: A Versatile Monomer for Functionalization of Polymers Obtained via RAFT
2-Isopropenyl-2-oxazoline (<i>i</i>POx) was
polymerized
for the first time via a controlled radical polymerization technique.
Reversible addition–fragmentation chain transfer (RAFT) polymerization
utilizing a dithiobenzoate-based chain transfer agent was employed
to form a backbone that is highly reactive toward thiols and acids.
Moreover, the statistical copolymerization of <i>i</i>POx
with methyl methacrylate (MMA) and <i>N</i>-<i>iso</i>-propylacrylamide (N<i>i</i>PAm) was investigated resulting
in two copolymer series with <i>i</i>POx content varying
from 100% to 13% (PDI = 1.37 to 1.21). The P(<i>i</i>POx-<i>stat</i>-N<i>i</i>PAm) copolymers displayed thermoresponsive
behavior in water as well as phosphate buffered saline at higher temperatures
in comparison to homopolymers of N<i>i</i>PAm due to the
hydrophilicity of the introduced <i>i</i>POx moieties (<i>T</i><sub>cp</sub> = 25 to 75 °C). Futhermore, <i>i</i>POx-based (co)polymers were functionalized by polymer analogous
addition reactions with thiophenol, benzoic acid and 4-azidobenzoic
acid in high conversions (74–100%). The latter adduct represented
a suitable building block for the synthesis of a graft copolymer consisting
of a PMMA backbone and poly(2-ethyl-2-oxazoline) (PEtOx) side chains
via copper-catalyzed azide–alkyne cycloaddition (CuAAC) of
PEtOx with alkyne terminus