Catalysis Design And Their Activity Toward Copolymerization Of Carbon Dioxide With Cyclohexene Oxide

In this thesis, a series of new catalysts are designed and used in copolymerization of CO₂ and cyclohexene oxide. The main results are summarized as follows:1. Seven enamine ligands for preparing catalysts are synthesized by means of condensation of P-diketone and aniline derivatives, and characterized with IR, NMR and elemental analysis.2. A series of novel catalysts are prepared first by using these precursors, ZnEt₂ and compounds with active hydrogen (methanol, isopropyl alcohol, and acetic acid). All of them can be applied in copolymerization of CO₂ and cyclohexene successfully. The catalytic efficiency is as high as 10⁴g polymer/mol cat.3. The effects of catalysts composition on copolymerization are also investigated. The results showed that suitable steric hindrance of ligands would benefit for the copolymerization of CO₂ and cyclohexene oxide. The catalytic activity of the catalyst with same ligand (L₁) is opposite to the acidity of compound with active hydrogen, that is, LiZn(O-ⁱPr) >L₁Zn(OMe) >L₁Zn(OAc).4. The structure, intrinsic viscosity and the thermal property of the resultant copolymers prepared are studied by IR, NMR, DSC, TG/DTG and Ubbelohde viscosity. The results showed that the ligand not only affected the catalyst activity, but also T_g, T_d and [η].