The synthesis of multiblock copolymer brush based on DSPAACand CuAACclick reaction

Multiblock copolymer brushes have broad application in thermoplastic elastomers, drug delivery, porous materials, and nanolithography due to their unique structure and properties. In this research, a novel multiblock copolymer brush (PHEA‐g‐PEG)x‐co‐ (PEG23)ywas synthesized by combining the efficient double strain‐promoted azide‐alkyne cycloaddition (DSPAAC) and copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) click reactions. The gel permeation chromatography (GPC), proton nuclear magnetic resonance spectrometer (1H NMR), Fourier transform infrared spectroscopy (FT‐IR), and atomic force microscopy (AFM) were used to characterize the prepared polymers. The results demonstrated that the novel multiblock copolymer brush was successfully prepared. The mole ratio was 1/0.84 between block PHEA‐g‐PEG and block PEG23, and the grafting density was 100%. The AFM image showed the morphologies of cylinder, sphere, and beads on a string owning to the random distribution of PHEA‐g‐PEG and PEG. A novel multiblock copolymer brush was synthesized by combining efficient DSPAAC and CuAAC click reactions. Firstly, polymer N3‐P(HEA‐alkyne)20‐N3was synthesized by SET‐LRP and subsequent deprotection, azidation and post‐modification reactions. Then the prepared polymer was reacted with N3‐PEG‐N3and DBA through DSPAAC click reaction to obtain the multiblock copolymer backbone (P(HEA‐alkyne)20)x‐co‐(PEG23)y. Finally, the multiblock copolymer brush (PHEA‐g‐PEG)x‐co‐(PEG23)ywas prepared by grafting the side chain onto the PHEA part of backbone through CuAAC click reaction.