Research In Preparing Polymer Using Bromoisobutyrylterminated β-CD As Initiator

Cyclodextrins are a number of cyclic oligosaccharides consisting several glucose units linkage through a-1,4-linkages. The most common is the a-, P-and y-cyclodextrins, respectively type of glucose by the 6,7,8 glucose units. The glucose unit contains two secondary hydroxyl groups at 2 and 3 position, one primary hydroxyl group at 6 position, easy to be Chemical modification. In theories, the cyclodextrins could be connected to different arms with various chemical characters by different reaction mechanisms; it can be a very good multi-functional macroinitiator, giving rise to polymers prepared by ATRP reaction. In the past decades, as the prices of the cyclodextrins were brought down greatly, the theoretical macroinitiator has become realistic, and their application fields were enhanced by the efforts of the scientists. This dissertation gave a detailed discussion on the synthesis and characterization of the polymers and star shaped polymers based on theβ-CD core, three parts of works were stated as below:1. Firstly, the functionalized macroinitiator 2Br-β-CD and 4Br-β-CD based on theβ-Cyclodextrins (β-CD) bearing functional bromide groups were synthesized. Its structure was characterized by 1H-NMR,FT-IR,TG. Determine their degree of substitution of 2 and 4, respectively. Explore the optimum conditions, and its solubility were discussed.2. Its structure was appraised with 1H-NMR,FT-IR,GPC,TG etc, using 2Br-β-CD and 4Br-β-CD as initiators,2,2'-bipyridine / CuBr as catalysts and a series of polymers, which are compounded by atom transferred radical polymerization synthesis in GMA, and MMA units. According to 1H-NMR analysis, the existence of polymer chain, at the end of bromine atoms, is confirmed, and the result of polymer is still a active long chain, so is the polymerization reaction, with which explains the ATRP reaction; Simultaneously, the obtained polymers can also be used as an initiator in order to trigger ATRP reaction further more. The thermal analysis demonstrates that these polymers have very good stability in thermal and optimize the reaction conditions..3. Its structure was appraised with GPC, FTIR, 1H NMR, using acyl bromidedβ-cyclodextrin as initiator and a series of polymers, which is confected in Solvothermal method. According to 1H-NMR analysis the existence of polymer chain, at the end of bromine atoms, is confirmed, and the result of polymer is still a active long chain, so is the polymerization reaction, and the obtained polymers can also be used as an initiator in order to trigger the reaction further more. Moreover, the TG behavior was studied by TG, only to find out that the stability is better, comparing with polymers, which are compounded in the method of ATRP.