Zn-based Catalyst And Its Catalytic Inorganic And Inorganic - Organic Hybrid L-lactide Ring-opening Polymerization Of Applied Research, The Preparation Of L-polylactic Acid

Based on the development of the catalysts with low toxicity and biocompatibility for the formation of L-PLA with high molecular weight, this thesis got the precursor H2L from the condensation of o-vanillin and 1,2-amino-cyclohexene. Further from the reaction of the precursor with Zn(OAc)2 on the condition of the definite molecular ratio, two new complexes monomer [ZnL(H2O)] and dimmer [Zn2L(OAc)2(H2O)] were obtained in good yields; on the other hand, the structure of the two catalysts were characterized by elemental analysis, infrared spectrum(IR), and nuclear magnetic resonance spectrometer (NMR).Secondly, started from the purified L-lactide, with the inorganic Zn(OAc)2, inorganic-organic hybrid complexes monomer [ZnL(H2O)] and dimmer [Zn2L(OAc)2(H2O)] as the catalysts, especially in consideration of the effect of the molar ratio of monomer and catalyst, polymerization time, polymerization temperature, with or without use of initiator, and the type of ending agents or precipitating agents on the characters of the obtained L-PLA, the polymerization procedure should be revealed.The conclusions were shown:(1) Either the inorganic Zn(OAc)2, inorganic-organic hybrid complexes monomer [ZnL(H2O)] or dimmer [Zn2L(OAc)2(HzO)] could be used to catalyze the ring-opening polymerization from the L-lactide.(2) For the catalyst of the inorganic Zn(OAc)2, the controllable polymerization was shown with the Mr of 103 and the PDI values of 1.15-1.53;For the catalyst of the monomer [ZnL(H2O)], the polymerization was shown with the Mr of 104 and the PDI values of 1.17-2.07;For the catalyst of the dimmer [Zn2L(OAc)2(H2O)], the controllable polymerization was shown with the Mr of 105 and the PDI values of 1.00-1.38; and the procedure of the molar ratio (800-2000:1) of monomer and catalyst, polymerization time (12-36 h), and polymerization temperature (115-145℃) was feasible.