Preparation Of Schiff Base Metal Complexes And Their Catalytic Properties For Lactide

Polylactic acid(PLA),poly?-caprolactone(PCL),and polycarbonate(PPC),which are important substitutes for traditional petroleum-based plastics,are new types of environmentally friendly polymer materials.One of the degradable polymer materials has excellent application prospects in various fields.They originate from the ROP of cyclic ester monomers.So far,ring-opening polymerization has been developed in the polymer field for nearly 20 years.Most of the theoretical foundations have been perfected.New hotspots such as block polymers of cyclic esters and regulatable switch polymerization are emerging in recent years.Regulations such as chemical regulation and allosteric regulation have been studied by many scholars.We have tried a completely new way of regulating polymerization,which can change the metal valence state of metal catalysts with Schiff base as the main structure through the Bulk Electrolysis.In a special electrolytic cell,under a threeelectrode system Cyclic Voltammetry is used to measure the voltage required for redox,and the catalyst metal center is given a certain voltage,so that the trivalent(III)and divalent(II)of the metal center are converted to each other,the monomers are polymerized during the ROP.Polymerization is used for intervention and control,and this kind of green electrochemical,simple operation method is used to realize switch polymerization.In this paper,we synthesized four Schiff base manganese chloride catalysts,and used this new type of electrochemical redox control to change the metal center valence of the catalyst to control lactide and ?-Caprolactone monomer polymerization,a Schiff base ferric chloride catalyst was synthesized and studied to regulate the polymerization of lactide and ?-caprolactone monomers after electrooxidation reduction The control effect of Schiff base cobalt chloride catalyst can polymerize lactide monomers when it is divalent,and it can catalyze polymerization when it is trivalent.Polycarbonate achieves alternate copolymerization of lactide and carbon dioxide through redox agents.Therefore,a new Schiff base cobalt was synthesized.This new electrochemical control method was used to control lactide monomer and phthalic anhydride(PA)without adding a redox agent.The monomers are regulated by catalytic copolymerization.