TY - JOUR
T1 - RAFT synthesis and aqueous solution behavior of novel pH- and thermo-responsive (Co)polymers derived from reactive poly(2-vinyl-4,4-dimethylazlactone) scaffolds
AU - Quek, Jing Yang
AU - Zhu, Yicheng
AU - Roth, Peter J
AU - Davis, Thomas Paul
AU - Lowe, Andrew
PY - 2013
Y1 - 2013
N2 - Well-defined homopolymers of 2-vinyl-4,4-dimethylazlactone (VDA) and AB diblock copolymers of VDA with N,N-dimethylacrylamide (DMA) and N-isopropylacrylamide (NIPAM) prepared by reversible addition-fragmentation chain transfer (RAFT) radical polymerization are reported. VDA homopolymers reacted with N,N-dimethylethylenediamine (DMEDA), N,N-diethylethylenediamine (DEEDA), and picoylamine (PA) give novel tertiary amine functional polymers that exhibit inverse temperature aqueous solution characteristics in the case of the DMEDA and DEEDA derivatives (provided they are not protonated) and a pH-dependent solubility for the PA species - it is soluble at low solution pH but becomes hydrophobic at ca. pH 4.0. VDA-DMA/NIPAM AB diblock copolymers are also readily modified with DMEDA, DEEDA, and PA to give a novel series of stimulus responsive block copolymers including tunably amphiphilic and schizophrenic species. DMEDA-DMA and DEEDA-DMA/NIPAM block copolymer derivatives undergo reversible temperature induced self-assembly in aqueous media by virtue of the inverse temperature solubility characteristics associated with these tertiary amino species. The aggregation behavior of these species is characterized using a combination of dynamic light scattering (DLS), 1H NMR spectroscopy and transmission electron microscopy (TEM). For the PA derivatives, schizophrenic behavior is demonstrated in AB block copolymers with NIPAM with normal and inverse micelles being readily accessible simply by controlling the solution pH or temperature. Self-assembled species derived from a DMEDA-DMA block copolymer, containing tertiary amino functionality in the core, can be readily core cross-linked, locking the self-assembled structure, using 1,10-dibromodecane as evidenced by DLS. The ability of examples of the smart block copolymers to sequester hydrophobic Nile Red upon application of a pH or temperature stimulus from an aqueous environment is also demonstrated. Finally, we show how, if desired, the DMEDA homopolymers can be further modified via the facile reaction with 1,3-propanesultone yielding the sulfopropylbetaine analogous materials.
AB - Well-defined homopolymers of 2-vinyl-4,4-dimethylazlactone (VDA) and AB diblock copolymers of VDA with N,N-dimethylacrylamide (DMA) and N-isopropylacrylamide (NIPAM) prepared by reversible addition-fragmentation chain transfer (RAFT) radical polymerization are reported. VDA homopolymers reacted with N,N-dimethylethylenediamine (DMEDA), N,N-diethylethylenediamine (DEEDA), and picoylamine (PA) give novel tertiary amine functional polymers that exhibit inverse temperature aqueous solution characteristics in the case of the DMEDA and DEEDA derivatives (provided they are not protonated) and a pH-dependent solubility for the PA species - it is soluble at low solution pH but becomes hydrophobic at ca. pH 4.0. VDA-DMA/NIPAM AB diblock copolymers are also readily modified with DMEDA, DEEDA, and PA to give a novel series of stimulus responsive block copolymers including tunably amphiphilic and schizophrenic species. DMEDA-DMA and DEEDA-DMA/NIPAM block copolymer derivatives undergo reversible temperature induced self-assembly in aqueous media by virtue of the inverse temperature solubility characteristics associated with these tertiary amino species. The aggregation behavior of these species is characterized using a combination of dynamic light scattering (DLS), 1H NMR spectroscopy and transmission electron microscopy (TEM). For the PA derivatives, schizophrenic behavior is demonstrated in AB block copolymers with NIPAM with normal and inverse micelles being readily accessible simply by controlling the solution pH or temperature. Self-assembled species derived from a DMEDA-DMA block copolymer, containing tertiary amino functionality in the core, can be readily core cross-linked, locking the self-assembled structure, using 1,10-dibromodecane as evidenced by DLS. The ability of examples of the smart block copolymers to sequester hydrophobic Nile Red upon application of a pH or temperature stimulus from an aqueous environment is also demonstrated. Finally, we show how, if desired, the DMEDA homopolymers can be further modified via the facile reaction with 1,3-propanesultone yielding the sulfopropylbetaine analogous materials.
UR - http://pubs.acs.org.ezproxy.lib.monash.edu.au/doi/pdf/10.1021/ma4013187
U2 - 10.1021/ma4013187
DO - 10.1021/ma4013187
M3 - Article
VL - 46
SP - 7290
EP - 7302
JO - Macromolecules
JF - Macromolecules
SN - 0024-9297
IS - 18
ER -