Polymerization-induced Self-assembly Based On Atom Transfer Radical Polymerization And Living Anionic Polymerization

Polymerization-induced self-assembly(PISA)has evolved over the past decade to be the most direct and efficient method for synthesizing diblock polymer nanoparticles with different morphologies.It has several advantages in the progress of the reaction,such as It is carried out under conditions of high concentration(10-50%by weight),and as a result,various forms can be formed,and the operation is also relatively simple.In order to study the PISA process under different living polymerization mechanisms,we applied atom transfer radical polymerization(ATRP)and living anionic polymerization(LAP)to the PISA process to further explore the PISA process.The results obtained are as follows:(1)Study on polymerization-induced self-assembly based on atom transfer radical polymerizationWe use the latest ATRP technology(Initiator Continuous Regeneration Catalyst(ICAR)ATRP)to use a copper catalyst with a concentration of ppm in the PISA process,which reduces the problems caused by metal copper contamination and post-treatment difficulties.During the course of the study,we used two different molecular weight polyethylene glycol monomethyl ether methacrylate(POEOMA)as a macroinitiator/stabilizer to induce monomeric benzyl methacrylate at 60°C.The polymerization self-assembly process of ester(BzMA)was carried out,and the concentration of CuIIBr2 and TPMA,the free radical initiator,the target polymerization degree(DP)of the monomer BzMA,the solid content and the temperature of the block polymer assembly morphology were systematically monitored.The effects of the evolution were finally verified by ~1H NMR,GPC,DLS and TEM.In addition,based on the results of this experiment,we also obtained the relationship between the molecular weight of the block polymer and the polydispersity of the assembled material.(2)Study on polymerization induced self-assembly based on living anionic polymerizationWe use LAP technology as the polymerization base,n-Heptane as the polymerization solvent,a small amount of tetrahydrofuran(THF)as the cosolvent,and n-butyllithium(nBu~-Li~+)as the initiator to initiate the monomeric isoprene.The diene(Is)is subjected to anionic polymerization.After the monomer conversion is completed,the monomer styrene(St)is further added to induce polymerization self-assembly of styrene,and as a result,polyisoprene(PI)is used as a shell.Polystyrene(PS)is a nano-self-assembled particle of the core.In addition,based on the LAP-PISA,we cross-linked the nanoparticles after the assembly with the cross-linking divinylbenzene(DVB),thereby further obtaining more structured polymer nanoparticles.Finally,combined with ~1H NMR,GPC,DLS and TEM results,it was successfully demonstrated that LAP technology can be used in the PISA process to synthesize diblock polymer nanoparticles with narrow molecular weight distribution...