An efficient route to macrocyclic polymers via “click” cyclization was presented.The α-bromine and ω-alkyne PMMA were prepared using the standard ATRP technique,initiated with propargyl 2-bromoisobutyrate,Cu(Ⅰ)Br...An efficient route to macrocyclic polymers via “click” cyclization was presented.The α-bromine and ω-alkyne PMMA were prepared using the standard ATRP technique,initiated with propargyl 2-bromoisobutyrate,Cu(Ⅰ)Br and N,N,N’,N″,N-pentamethyldiethylenetriamine(PMDETA).Azidation of the terminal bromine was followed in DMF with sodium azide,and α-azide,ω-alkyne PMMA precursor was obtained.Then the “click” cylcization of precursor between terminal azide and alkyne was carried out under the catalysis of CuBr/PMDETA,during the course of the reaction,a pseudo-high dilution technique was utilized to ensure the favored intramolecular cylcization.The nearly complete cylcization has been confirmed by a combination of IR,1H NMR and GPC analysis,and cyclo-PMMA with an Mn of 15000,PDI of 1.38 was obtained.展开更多
A new effecient catalyst system(FeCl 3/2PPh 3) for the “living”/controlled radical polymerization of butyl methacrylate by a reverse ATRP process was reported in this paper.With the presence of this catalyst system,...A new effecient catalyst system(FeCl 3/2PPh 3) for the “living”/controlled radical polymerization of butyl methacrylate by a reverse ATRP process was reported in this paper.With the presence of this catalyst system,the number average molecular weights of the obtained polymer increased in direct proportion with monomer conversion,and the MWDs (molecular weight disctributions) were narrow throughout the reactions(1 17< w/ n<1 22).This reaction system did not include the conventional initiators which were used to generate the primary radicals.展开更多
文摘An efficient route to macrocyclic polymers via “click” cyclization was presented.The α-bromine and ω-alkyne PMMA were prepared using the standard ATRP technique,initiated with propargyl 2-bromoisobutyrate,Cu(Ⅰ)Br and N,N,N’,N″,N-pentamethyldiethylenetriamine(PMDETA).Azidation of the terminal bromine was followed in DMF with sodium azide,and α-azide,ω-alkyne PMMA precursor was obtained.Then the “click” cylcization of precursor between terminal azide and alkyne was carried out under the catalysis of CuBr/PMDETA,during the course of the reaction,a pseudo-high dilution technique was utilized to ensure the favored intramolecular cylcization.The nearly complete cylcization has been confirmed by a combination of IR,1H NMR and GPC analysis,and cyclo-PMMA with an Mn of 15000,PDI of 1.38 was obtained.
文摘A new effecient catalyst system(FeCl 3/2PPh 3) for the “living”/controlled radical polymerization of butyl methacrylate by a reverse ATRP process was reported in this paper.With the presence of this catalyst system,the number average molecular weights of the obtained polymer increased in direct proportion with monomer conversion,and the MWDs (molecular weight disctributions) were narrow throughout the reactions(1 17< w/ n<1 22).This reaction system did not include the conventional initiators which were used to generate the primary radicals.
