Preparation Of Cyclic Polymer Based On Living/Controlled Radical Polymerization

In comparison with tradition free radical polymerization,controlled living radical polymerization(CRP)could control the microstructure,degree of polymerization,and molecular weight distribution of polymers,as well as the design of polymer structure.At the moment,polymerization methods of CRP include Iniferter,NMP,ATRP,RAFT and etc.As the most common method in studies of CRP,ATRP/RAFT has been wildly adopted in researches since discovered.In this paper:(1)A new universal type of RAFT agent has been designed.With the modification of external hydrogen ion environment,the new agent can initiate not only the polymerization of active monomers such as styrene and etc.but also that of inert monomers such as vinyl acetate,which produces well control PDI polymer.Also,the obtained polyvinyl acetate has been the copper(I)-catalyzed alkyne-azide cycloaddition(CuAAC)so that by cyclic reaction to form Cyclic polymer.(2)Based on cyclopropenone-masked dibenzocyclooctyne,a type of ATRP agent and RAFT agent have been newly designed and compounded,and with the new RAFT reagent,methyl methacrylate has been induced polymerization so that well control PDI polymers was obtained.(3)A double side initiator ATRP agent has been newly designed and used to initiate the sytene.With the help of TEMPO,the compound formed during the process has been modified the two side and then become azide group.As the same time,with the ultraviolet light,the cyclopropenone-masked dibenzocyclooctyne would take photochemical reaction and then produce acetylene bond.The azide group and acetylene bond would in situ to ring-close the linear polymers and produce the corresponding cyclic polymers based on the strain promoted azide–alkyne cycloaddition(SPAAC)click reaction,so that a tadpole-shaped topological macromolecules would be produced,which could re-obtain linear polymer under the 180oC for xylene solution.(4)A type of RAFT reagent having the cyclopropenone-masked dibenzocyclooctyne has been newly designed which could initiate monomers of sytene and tert-Butyl acrylate to form PDI-controllable polymers,which would be form ring polymers through the classic SPAAC reaction.