Construction Of Novel Concurrent Reaction (Polymerization) Via A Combination Of CuAAC And CRP

“Click Chemistry”is recognized by chemists as one of the most simple and efficient organic reactions and emerged as one of the most powerful tools in synthesizing various kinds of advanced macromolecular materials.Among all click reactions,the copper（I）-catalyzed azide-alkyne cycloaddition（CuAAC）is the most classic click rection,which has wide application in solid phase synthesis,polymer synthesis,drug release,and biochemistry.CuAAC click reaction has become a hot topic for chemists.The development of“one-pot”technology greatly simplifies the experimental and post-processing steps,but it makes challenging to realize well-controled polymerization because of the combination of more than one reaction.This paper is construction of novel concurrent reaction（polymerization）via a combination of CuAAC and CRP to produce well-defined functional polymers.Firstly,Electron transfer mediated concurrent polymerization combining CuAAC polymerization and CRP was successfully employed to produce brush-like copolymers.Secondly,copper（II）thioxanthone carboxylate[Cu（TX）₂]was successfully designed and synthesized.Opened to air and sunlight-driven“CuAAC&ATRP”concurrent reaction was carried out using Cu（TX）₂ as photocatalyst and oxygen scavenger.Furthermore,the multiblock functional copolymers with defined molecular weights and monomer sequence were synthesized based on the above work.The main contents are divided into the following two parts:1)Electron transfer mediated“CuAAC&CRP”concurrent polymerization:CuAAC polymerization behavior of AB₂ monomers（possessing one alkyne group and two azide groups）was firstly investigated.From the results of GPC,the controlled polymerization of AB₂ monomers can be realized using Cu（0）/PMDETA as catalyzed system;The kinetic study indicated that CuAAC polymerization was following chain-growth mechanism;However,the degree of polymerization determined by ¹H NMR was relative low（DP=13）.Moreover,ABC inimer acting as clickable monomer and initiator was successfully employed to combine CuAAC polymerization and CRP to prepare brush-like copolymers.The results from ¹H NMR and FT-IR comfirmed the structure of the obtained copolymers.Furthermore,it is found that there is strong collaborative effect and compatibility between CuAAC polymerization and CRP to improve the controllability.2)Photo-induced electron transfer mediated“CuAAC&CRP”concurrent reaction under open conditions:The ATRP of MMA was first investigated under an oxygenfree atmosphere by employing Cu（TX）₂ as a photocatalyst and natural sunlight as light source.The polymerization behavior possessed the characteristics of“living”/controlled radical polymerization:the first-order kinetic plots,narrow molecular weight distribution,the linear relationship between molecular weights and the monomer conversions.Then,the opened to air and sunlight-driven ATRP for MMA was successfully conducted using Cu（TX）₂ as photocatalyst and oxygen scavenger.Furthermore,sunlight-driven“CuAAC&ATRP”concurrent reaction combining photo-induced ATRP and CuAAC reaction,was carried out using azidomethyl benzene（AMB）and propargyl methacrylate（PgMA）as a model open to air.Moreover,CuAAC reaction and ATRP could be immediately stopped by removing the light source and bubbling oxygen into the system at the same time,and be reversibly reactivated by irradiation with sunlight.Finally,the sequence-controlled multiblock functional copolymers were successfully synthesized by iterative monomer additions under fully open conditions.