Ring-opening Copolymerization Of Cyclic Anhydrides And Propylene Oxide Catalyzed By Zinc Glutarate

With the increasing of population and developing of science and technology,people’s requirement towards materials’properties is gradually increasing day by day,high-performance polymer play a very important role in many fields, Polyesters has apotentially wide range of applications used in medical materials owing to itsenvironment-friendly. Ring-opening polymerization of cyclic anhydrides withepoxides is an effective method to synthesize polyesters, especially to synthesis ofaliphatic polyesters and functional polyesters. However, there are still some problemsin the synthesis of polyester. It’s difficult to prepare polyesters in a highly alternatingcopolymerization of cyclic anhydrides and epoxides which afforded high molecularweight copolymers with narrow molecular weight distributions. Therefore, it’ssignificant to develop effective catalysts for the copolymerization.This thesis aims to study on the ring-opening copolymerization of propyleneoxide (PO) and Cyclic Anhydrides catalyzed by zinc glutarate (ZnGA). The contentincludes:First, ring-opening copolymerization of phthalic anhydride and propylene oxidecatalyzed by zinc glutarate to synthesize polyester, the Mn of the polyester achieved4.7×10~3, the molecular weight distribution index is very narrow. The structure ofpolyester was confirmed by the1H NMR and FT-IR spectra. The effect of reactionconditions on the copolymerization was investigated, the results shown that the yieldof polymer increase with increasing of the reaction temperature and time. Theoptimum reaction conditions: the monomer molar ratio of PAto PO was1, the catalystconcentration was0.01g/ml, the temperature was100°C and the reaction time was20hours.Second, ring-opening copolymerization of maleic anhydride and propylene oxideused zinc glutarate as catalyst to synthesize polyester, the Mn of the polyestermolecule achieved4.4×10~3, the molecular weight distribution index close to1. thepolymer yield was96.4%in100℃,40hours, catalyst concentration was0.01g/ml.As the reaction temperature and the catalyst concentration increased, the high yield ofcopolymer was achieved. The monomer molar ratio had a significant impact on the structure of the polymer. The optimum reaction conditions: the monomer molar ratioof MA to PO was1, the catalyst concentration is0.01g/ml, the temperature was100°C and reaction time was40h. the results showed that the transition of polyesterfrom cis-to trans-at room temperature, and the conversion rate increases withincreasing of the reaction time.Third, ring-opening copolymerization of succinic anhydride with propylene oxidecatalyzed by zinc glutarate to synthesize polyester, the Mn of the polyester moleculeachieved4.6×10~3, the molecular weight distribution index close to1. The yield of thepolymer increases with increasing of the reaction time and temperature, the highestyield of the obtained polymer was93.6%. There are obvious changes on the contentof polyether with increasing PO monomer molar content in the copolymerization. Theoptimum reaction conditions: the monomer molar ratio of PA and PO was1, thereaction temperature was100℃, the reaction time was50h, the catalyst concentrationwas0.01g/m.Finally, ring-opening copolymerization of itaconic anhydride with propyleneoxide catalyzed by zinc glutarate, the polyester were characterized by the1H NMR,FT-IR, the results showed that the the polyester formed cross-linking structure. Studyon the reaction conditions on the copolymerization. The results shown that themonomer molar ratio was1, the gel content of the polymer was89.4%. The yield ofpolymer increased with the increasing of the reaction temperature. The optimumreaction conditions: monomer molar ratio was1, the reaction temperature was100℃,catalyst concentration was0.01mg/ml and the reaction time was96h.