Based On Dmaema Stimulus Responsive Block / Synthesis And Properties Of Comb-shaped Copolymers

1.The copolymer PEG-b-PDMAEMA were synthesized by ATRP and characterized by FTIR,¹H NMR spectroscopy.Rheological measurements were used to characterize the rheological properties in different pH and ionic strength environments.It was found that the lower critical solution temperature(LCST) decreased with the increase of pH and ionic strength.2.ICs formed by stimulus-responsive block copolymer PEG-b-PDMAEMA with different block ratio andα-cyclodextrin(α-CD) was studied.The stoichiometry value of [EO]/α-CD calculated from ¹H-NMR data was 3.19 for PEG₁₀₂-b-PDMAEMA₄₆/α-CD and 3.42 for PEG₁₀₂-b-PDMAEMA₉₆/α-CD.The rheological measurement shows that the viscosity of the hydrogels greatly diminished as they were sheared and the hydrogel formed by copolymer with higher ratio of unit EG to DMAEMA has higher viscosity and modulus than that with lower ratio.The fluorescence measurement were used to study the kinetic of the formation of the ICs,it shows that the increase of pH can promote this process.The TEM results showed that morphologies could be changed from spherical to vesicular.The diameter of the formed micelles increased with the increase of pH and ionic strength.3.Poly(EO-co-EPEE) is successfully prepared by anionic polymerization and then hydrolyzed in the acidic conditions to get linear poly(EO-co-Gly).The brush copolymer poly(EO-co-Gly)-g-PDMAEMA was synthesized via ATRP and the results of ¹H-NMR and GPC indicated that it was successfully prepared.The self-assembly studies showed that the LCST of the aqueous solution decreased with the increase of pH and ionic strength,and the diameter of the formed micelles increased with the increase of pH and ionic strength.4.The graft copolymerization of hydroxyethyl cellulose(HEC) and DMAEMA was initiated by cerium(Ⅳ) ammonium nitrate(CAN)/HCl.The final graft copolymer was characterized by FTIR and ¹H-NMR,and the possible mechanism of the copolymerization was researched.Rheological measurement was used to study the LCST.The self-assembly behavior of the copolymer showed that the diameter of the micelle increased with the increasing of the pH and ionic strength of the solution.