Based Asymmetric Seats Furosemide Bases - Development And Catalytic Cobalt-based Catalyst For Preparing A Polyester Research

Polyesters, due to their better biocompatibility and biodegradability, were widely used in medicine, agriculture, biodegradable materials, etc. In the synthesis of polyesters, the development of needed catalysts has been one of the focuses of scientific researches, so in this thesis, series of new catalysts are designed, and applied to study preparations of polyesters.Two series of asymmetric bis-Schiff-base Co(III) complexes are synthesized and characterized by element analysis (EA), infrared spectrum (FT-IR), nuclear magnetic resonance spectrum (NMR) and X-ray single-crystal diffraction (XRD); and the two series of asymmetric bis-Schiff-base Co(III) complexes are used as catalysts for the ring-opening copolymerizarion of cyclohexene oxide (CHO) and maleic anhydride (MA),4,4’-oxydiphthalic Anhydride (ODPA) and MA. For the obtained copolymers, the molecular weight size (Mn or Mw) and the molecular weight distribution (PDI=Mw/Mn) are determined by gel permeation chromatography (GPC). Moreover, the obtained different polymers are characterized by the FT-IR and1H NMR. Moreover, the relationship between the structures of different catalysts and the catalytic behaviors and the effects of polymerization method, molar ratio of monomer, co-catalyst, polymerization time and polymerization temperature on the catalysis are also studied in detail.Firstly, the synthesis and characterization of the half-unit schiff base precursor HL0, five asymmetric bis-Schiff-base ligands H2L1～H2L5and the two series of catalysts[Go(L1)](OAc)]～[Co(L5)(OAc)] and [Co(L1)(CI)]～[Co(L5)(CI)] have been finished.Secondly, with the two series of complexes as the catalysts, their detailed ring-opening copolymerizations of MA and CHO have been checked. Moreover, with complex [Co(L5)(CI)] as the selected catalyst, different monomers, such as MA and styrene oxide (SO) and phthalic anhydride (PA) and CHO, PA and SO have been copolymerized. And the steric effects, the electronic effects and anionic effects of the catalysts on the ring-opening copolymerizations have been concertrated.Thirdly, using two series of catalysts respectively to further study the ring-opening copolymerizations of the dianhydride ODPA and CHO, from which the steric effects, the electronic effects and anionic effects of the catalysts on the ring-opening copolymerizations are checked. Finally, the effect of polymerization process on the copolymerizations was investigated. For the copolymerization of MA and CHO in melting condition, the optimum condition for [Co(L5)(CI)]/DMAP is as following:the polymerization time of150min, the polymerization temperature of110℃, the molar ratio of monomer and catalyst of250:250:1:1; from which, the largest catalytic activity is7.52x103g·mol-1h-1, Mn is17.062x103g·mol-1and PDI is1.41. As to the ODPA and CHO solution copolymerization, the optimum condition for [Co(L5)(CI)]/DMAP is:the polymerization time of300min, the polymerization temperature of110℃, the molar ratio of monomer and catalyst of125:250:1:1, where the largest catalytic activity is7.98x103g·mol-1h-1, Mn is3.287x103g·mol-1and PDI is1.42.