Synthesis of Multiblock Copolymers by Coupling Reaction Based on Self-Assembly and Click Chemistry

Abstract

Diends-azido-terminated and diends-alkynyl-terminated poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymers (N 3 -PEO-b-PPO-b-PEO-N 3 and HCtC-PEO-b-PPO-b-PEO-CtCH) were respectively prepared and used together as the precursors for multiblock copolymer synthesis through coupling reaction by combination of self-assembly and click chemistry. The self-assembly of equimolar resultant triblock copolymers in water, a selective solvent for PEO, results in a core-shell structure with the insoluble and collapsed PPO blocks as the core and the soluble and swollen PEO blocks as the shell. The self-assembly concentrates and exposes the azido and alkynyl end groups on the periphery. The multiple click coupling reactions between the self-assembled diends-functionalized triblock copolymers were performed, leading to the highly efficient formation of -(-PEO-b-PPO-b-PEO-) nmultiblock copolymer chains. In comparison, the click coupling reaction was also presented in N,N-dimethylformamide (DMF) solution without self-assembly. It was found that the efficiency of the coupling reaction was very low, and no long multiblock copolymer chains were produced.

Effect of UV irradiation on the physicochemical properties of collagen stabilized using aldehydes

“…On the reverse, as in the case of the coupling achieved with the diisocyanate spacer, coupling rates decreased with higher diblock molar mass (Table 2, entry 11). This result was in accordance with the literature in which it was shown that the synthesis of block copolymers by “click” chemistry was only reported for relatively short polymers or oligomers 18, 19, 41. It is also important to notice that under these conditions, the “click” reaction was possibly due to both temperature and the copper/PMDETA catalytic system 42.…”

Applications of Orthogonal “Click” Chemistries in the Synthesis of Functional Soft Materials

“…1,13,27–30,33,36,48,54,56,63,79–89 This method offers an extremely simple route to high fidelity end-functional polymers for subsequent modification by CuAAC. The influence of the polymeric repeat unit on the efficiency of chain end modification was recently probed by the Matyjaszewski group through a study using azido-based model compounds to compare the rate of the functionalization reaction with the nature of the monomer unit from which the terminal halogen was displaced.…”

Click Cross-Linking-Improved Waterborne Polymers for Environment-Friendly Coatings and Adhesives

“…15 As one of the most effective chemical reactions, click chemistry has been widely used in the synthesis, modification, and engineering of polymers, to obtain linear or branched polymers, 16,17 to conjugate or link small molecules or macromolecules, [18][19][20][21] , and to crosslink click-suitable polymers. [22][23][24][25][26] The highly stable aromatic structure of triazole has the advantages of being tolerable to acidic, basic, and oxidative mediums, 27 mimicking amide groups and acting as hydrogen bond acceptors to improve mechanical strength.…”