Synthesis And Properties Of Multicompartment Nanoparticles Of ABC Miktoarm Star Polymers And Block Copolymer Nanoparticles With Different Hydrophilicity

Block copolymer nanoparticles have broad application prospects in many fields due to their various morphologies,and have always been the focus of polymer chemistry.At present,researchers have been able to synthesize nano-assemblies with diverse morphologies through various methods.Meanwhile,the properties and application of nanoparticles still need more attention.This paper includes three aspects.For the first part,multicompartment nanoparticles of m-ABC miktoarm star polymers were synthesized by combining the click reaction of Cu(I)-catalyzed Huisgen cycloaddition and seeded RAFT dispersion polymerization,and the effect of polymers structure on the interfacial properties of nanoparticles was explored;For the second part,block copolymer nanoparticles with different hydrophilicity were prepared through RAFT dispersion polymerization and the properties of those nanoparticles were studied.For the third part,switchable RAFT polymerization was realized with the assistance of azobenzenes.This thesis mainly introduces the first and second parts,and the detailed content is as follows: 1.Synthesis of Multicompartment Nanoparticles of ABC Miktoarm Star Polymers by Seeded RAFT Dispersion PolymerizationPolymeric multicompartment nanoparticles(MCNs)consisting of a microphase-segregated core and a solvophilic corona have recently gained much attention due to their special structure and promising applications.Consequently,linear ABC triblock copolymers,including a fluorinated block,ABC miktoarm star terpolymers,and ABCA or ABCBA multiblock copolymers,are usually employed.In these polymers,ABC miktoarm star terpolymers,with a character that all the A,B,and C segments are connected at one point,are the most employed,since this structure is helpful for microphase-segregation between the solvophobic B and C blocks.Up to now,some MCNs of ABC miktoarm star terpolymers have been prepared via micellization in the selective solvent for the A segment.However,this strategy has some intrinsical shortcomings which greatly limit the application of MCNs.Polymeric multicompartment nanoparticles(MCNs)of m-ABC miktoarm star polymers composed of poly(N,N-dimethylacrylamide)(PDMA),poly(butyl methacrylate)(PBMA),and polystyrene(PS)were synthesized by Cu(I)-catalyzed click reaction and seeded RAFT dispersion polymerization.The synthesized MCNs have a solvophobic PBMA core with separate segregated PS microdomains and a solvophilic PDMA corona.The size and/or morphology of MCNs are correlative to the length of PDMA,PBMA,and PS segments.Ascribed to the characteristic structure,MCNs of m-DBS can decrease interfacial tension in n-hexane/water,which is much superior to linear diblock copolymer nanoassemblies.2.Synthesis and properties of nanoparticles of diblock copolymers with different hydrophilicityIn this section,spherical nanoparticles of diblock copolymers with different hydrophilicity were prepared through general RAFT dispersion polymerization of styrene in the 80/20 ethanol/water mixture mediated by different macro-RAFT agents respectively,which were synthesized by solution RAFT random copolymerization of acrylic acid(AA)and various monomers.And the properties of those nanoparticles were explored by experiments of interfacial tension and contact angle.It was found that the composition and degree of the hydrophilic block of diblock copolymers can influence closely the interface properties of nanoparticles and hydrophilicity of epoxy films containing diblock copolymers.