A double thermoresponsive ABC-type triblock copolymer （poly（ethyleneglycol）-block-poly （2-（2-methoxyethoxy）ethyl methacrylate）-block-poly（2-（2-methoxy ethoxy） ethyl methacrylate-co-oligo（ethylene glycol）...A double thermoresponsive ABC-type triblock copolymer （poly（ethyleneglycol）-block-poly （2-（2-methoxyethoxy）ethyl methacrylate）-block-poly（2-（2-methoxy ethoxy） ethyl methacrylate-co-oligo（ethylene glycol） methyl ether methacrylate, PEG-b-PMEO2MA-b-P（MEO2MA-co-OEGMA）） was designed and synthesized by reversible addition- fragmentation chain transfer polymerization （RAFT）. The ABC-type triblock copolymer endowed a thermal-induced two- step phase transition at 29 and 39 ℃corresponding to the thermosensitive properties of PMEOzMA and P（MEO2MA-co- OEGMA） segments, respectively. The two-step self-assembly of copolymer solutions was studied by UV transmittance measurement, dynamic light scattering （DLS）, transmission electron microscopy （TEM） and so on. The triblock copolymers showed the distinct thermosensitive behavior with respect to transition temperatures, aggregate type and size, which was correlated to the degree of polymerization of thermosensitive blocks and the molar fraction of OEGMA in the P（MEO2MA- co-OEGMA） segments. In addition, micelles could further aggregate to form the hydrogel by the self-associate of PEG chains under the abduction of the concentration and temperature. The transition from sol to gel was investigated by a test tube inverting method and dynamic rheological measurement.展开更多
基金financially supported by the National Natural Science Foundation of China(No.20973106)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT_14R33)
文摘A double thermoresponsive ABC-type triblock copolymer （poly（ethyleneglycol）-block-poly （2-（2-methoxyethoxy）ethyl methacrylate）-block-poly（2-（2-methoxy ethoxy） ethyl methacrylate-co-oligo（ethylene glycol） methyl ether methacrylate, PEG-b-PMEO2MA-b-P（MEO2MA-co-OEGMA）） was designed and synthesized by reversible addition- fragmentation chain transfer polymerization （RAFT）. The ABC-type triblock copolymer endowed a thermal-induced two- step phase transition at 29 and 39 ℃corresponding to the thermosensitive properties of PMEOzMA and P（MEO2MA-co- OEGMA） segments, respectively. The two-step self-assembly of copolymer solutions was studied by UV transmittance measurement, dynamic light scattering （DLS）, transmission electron microscopy （TEM） and so on. The triblock copolymers showed the distinct thermosensitive behavior with respect to transition temperatures, aggregate type and size, which was correlated to the degree of polymerization of thermosensitive blocks and the molar fraction of OEGMA in the P（MEO2MA- co-OEGMA） segments. In addition, micelles could further aggregate to form the hydrogel by the self-associate of PEG chains under the abduction of the concentration and temperature. The transition from sol to gel was investigated by a test tube inverting method and dynamic rheological measurement.
