Synthesis Of Star-Shaped Polymer With Porphyrin-Core By ATRP And Its Self-Assembly Behavior Study

At present, the products of radical polymerization are in the majority (about 60%) of the polymers, which indicate the essentiality of radical polymerization. This is because the most kinds of vinyl monomers can be polymerized by radical polymerization under mild conditions. Furthermore it can react in water without oxygen. On the other hand, more monomers can be copolymerized which produced more radical polymers. There are some shortcomings in the field of traditional radical polymerization, such as the polymerization possess the behavior of out controlled which arose the results of lose of molecular weights, molecular distributions, molecular structure, molecular composing and end functions. Thus, the properties of polymer from radical polymerization were impaired. Some scientists pay more attention to synthesize the polymer with well-definded structure from living polymerization. Jinshan Wang and K.Matyjaszewski etc introduced a kind of living radical polymerization (Atom Transfer Radical Polymerization ATRP), which include initiator (halogenations alkyl), catalyzer (CuCl), ligands (bpy) and monomer (MMA). At the primary phase of initiated stage, the reducing agent of catalyzer undergoes a one-electron oxidation with concomitant abstraction of a halogen atom (X) from a dormant species R-X. Thus, the living species and dormant species were formed. Living species may react with monomer or form dormant species for capturing halogen atom, which induced a lower concentration of living species. Because the fast reversible dynamic balances were established we could synthesize the target polymers or oligomers, which possess well-defined structure, preconcerted molecular weights and low molecular distributions.With the rapid development of technology, more and more polymer materials with function and intellect are required. Some kinds of functional polymer materials such as nanocomposite, electrochemical materials, paramagnetic materials and inorganic/organic hybrid materials attract more attention of scientists. Using fields of these materials involved medical polymer materials (iatric materials medicament transportation, corporal apparatus), electric materials, illuminant materials, non-linear optical field, polymer catalyzer, analytical separate film, polymer sorbents and energy storage of transforming phase. In recently, because the systems of ATRP were studied more and more, many scientists pay more attention to the functional materials using ATRP. Comparing with others"living"/controlled methods the ATRP are better at design of molecule. Now, the applicable studies systems of ATRP are few and far between. Scientists pay more attention to synthesize the functional materials using ATRP. Comparing with other methods of"living"/ controlled polymerization the ATRP is good at design. Using ATRP method we also synthesize many kinds of polymers such as block, star, graft, hyper branched (multifunctional) copolymers, inorganic/organic hybrid materials and nonmaterial etc.The aim of this paper is to investigate and study the star-shaped polymer with Porphyrin-Core. There are kinds of star shaped homopolymer , block copolymer and Star- combtype copolymer were synthesized. In addition, self-assembly behavior of copolymers in aqueous media was also studied by the numbers.In the first section of Chapter 1, we enumerated the history of radical polymerization and sum up the merits and drawbacks. More importantly, summarize the development of ATRP. At the same time, we also sum up the methods of Porphyrin synthesizs and enumerated the applications, especially the Porphyrin-Polymer, in the fields of investigation recently. In the last section, we reviewed the star shaped polymer and block copolymer self assembly aggregates formed in the aqueous solution.In Chapter 2, we used the method of improved Adler-Longo to synthesize the 5,10,15,20-tetra(4-hydroxyphenyl)porphyrin (THPP) first。Columniation chromatography were used for the purification of THPP。Then,5,10,15,20-tetra(4-hydroxyphenyl)porphyrin (THPP) was converted to Tetrafunctional star-shaped macroinitiator ( Porphyrin-Br ) by the esterification with 2-bromopropanoyl bromide. The four functionality Star-shaped initiator for ATRP investigated by UV-VIS IR and NMR measurement. In the UV-VIS spectrum, the B(soret) band and Q band of the porphyrins'characteristic absorbance were found. We can also find the framework vibrancy picks of the porphyrins'characteristic absorbance in the IR spectrum. Above-mentioned, we successfully synthesized a kind of new-style four functionality Star-shaped initiator for ATRP with the Porphyrin-Core.In the first section of Chapter 2, the star-shaped polymer (Porphyrin-PMMA) with porphyrin-core was synthesized by the atom transfer radical polymerization (ATRP) using the new-style four functionality Star-shaped initiator and CuCl/2,2'-bipyridine as the catalyst system. The structure and molecular characteristics of the polymer were investigated by UV-Vis, IR and NMR measurement. Kinetics analysis indicated a"living"/controlled radical polymerization.The results of the NMR,GPC and IR spectrum showed that the structure of the Porphyrin-PMMA was in accord with with our design. The DLS indicated that the distribution was narrow and the size was homogeneous in different initializing consistency. The AFM image of the nanopaticles for the Porphyrin-PMMA shows that the size was smaller then in the DLS. That was accord to the typical rules of the self-assembly process.Triumphantly we synthesized the Porphyrin-PGMA and Porphyrin-PNIPAM, and proved the structure of Star-shaped by NMR and IR spectrum. In the text of UV-Vis spectrum, the result that the Q band and B(Soret) band which was the porphyrins'proper absorbance is consistent with preceding conjectures. GPC indicates that the outcome accords with living and maneuverability polymerization.It is specially important that the reaction of MMA was carry through in the room temperature and the PDI was narrow. That lay the foundation for the industrialization's extensive use. On the research of the emperature sensitivity of Porphyrin-PNIPAM, we substantiate that the Star-shaped polymer have the similar LCST as the linear PNIPAM by the change of dynamic viscosity following the change of temperature.In the third section of Chapter 3, we make good to get a new star-shaped block polymer with the porphyrin-core by using Porphyrin-Br and adopting continuous ATRPs. GPC and NMR show the block polymer has exquisite configuration.In the IR spectrum , we not only look into the characteristic picks of the PGMA and PMMA but also find the framework vibrancy picks of the Porphyrin-core.In the UV-Vis spectrum, characteristic absorbance is observed that is exactly the same as we expected.In the Chapter 4, we study the ATRP with the Porphyrin-Br as the polymerization initiator and the St as the monomer. GPC bears out"living"/controlled radical polymerization character. We make use of the NBS/AIBN system to convert the Porphyrin-PSt to the macromolecule initiator and for the first time, we finally get a new-style Star-combtype polymer.The results of the testing indicates that the Porphyrin-PSt-g-PGMA's structure is as the same as our design.This technique find a new way to synthesize this star-combtype polymer which have the Porphyrin-core and the framework of the PSt.