The Development Of Visible Light Initiate Polymerization-induced Self-assembly And Application In The Synthesis Of Polymer Nanomaterials

Photoinitiated polymerization-induced self-assembly?Photo-PISA?based on reversible addition-fragmentation chain transfer?RAFT?dispersion polymerization has become a new method for preparing polymer nanomaterials.PISA can rapidly and reliably prepare well-defined morphologies at high solids contents,which overcome the drawbacks of traditional self-assembly methods?low yield,tedious operation and poor repeatability?.Moerover,in contrast to thermal initiated PISA,Photo-PISA can conduct under mild conditions with good control ability.In order to expand the promise of photopolymerization in PISA,as well as the mechanism study of Photo-PISA.In this thesis,we will develop several new photo-PISA systems and synthesize a series of deblock copolymer nanomaterials.The main contents are listed as follows:1.Sodium bis?methanesulfonyl?phosphonate?BAPO-Na?and phenyl sodium salt-trimethylbenzoyl phosphite?SPTP?were used as photoinitiators.4-cyano-4-[?dodecyl thiocarbonyl?thialkyl]valerate?CDPA?and 4-Cyano-4-?ethylthiocarbonothioylthio?pentanoic acid?CEPA?were used as RAFT reagents.Poly?glycerol methacrylate??PGMA?prepared by RAFT polymerization was used as macro-RAFT reagent.Diblock copolymer nanomaterials with different morphologise were prepared by Photo-PISA in water using blue light?465 nm?or violet light?405 nm?.TEM measurement and kinetic studies show that temperature and light intensity had significant effects on the rate of polymerization.Moreover,the morphologise of polymer nanomaterials at different temperatures were different even with the same hydrophobic chain length.In contrast,the morphologies of the polymer nanomaterials prepared under different wavelengths were the same.In summary,Finally,a fully one-pot photoinitiated RAFT polymerization was employed to prepare polymer nanomaterials with different morphologies.2.For the photo-and thermal-comediated PISA,poly?ethylene glycol?monomethyl ether(mPEG₁₁₃)was used as the macro-RAFT agent,SPTP was used as the photoinitiator and HPMA was used as the monomer.A series of polymer nanomaterials were prepared by changing reaction temperatures,the length of hydrophobic chain and monomer solids contents.The kinetic study shows that more than 95%monomer conversion could be achieved within 15 min at 40 ^oC.TEM measurement show that the morphologies of polymer nanomaterials changed from vesicles to large compound vesicles and finally microspheres as the increase of reaction temperature.Epoxy-functionalized large compound vesicles were prepared by adding glycidyl methacrylate?GlyMA?into the reaction.The obtained epoxy-functionalized large compound vesicles could be further cross-linked by reacting with ethylene diamine.The cross-linking could significantly enhance the stability of large compound vesicles against good solvent as well as surfactant.3.Poly?diacetone acrylamide??PDAAM?prepared by RAFT polymerization was used as the macro-RAFT agent.2,4,6-Trimethylbenzoyl-diphenylphosphine oxide?TPO?was used as the photoinitiator and tert-butyl acrylate?tBA?was used as the monomer.Photo-PISA was then conducted in an ethanol/water mixture.Diblock copolymer nanomaterials with different morphologies were prepared by changing the monomer concentration and the length of the hydrophobic block,and a detailed morphological phase diagram was constructed.Kinetic study show that the photo-PISA can be separated into two stages,homogenous polymerization stage and heterogeneous polymerization stage.More than 95%monomer conversion was achieved within 30 min.Polymer nanomaterials with lamellar morphology were prepared by copolymerization of isobornyl acrylate?IBOA?and t BA.The obtained polymer nanomaterials contain a large number of ketone groups on the surface,allowing the shell-cross-linking by the reaction between ketone and diamine.The obtained shell-cross-linked polymer nanomaterials exhibited excellent stability against good solvent as well as surfactant.