Design And Synthesis Of CGC Metallocene Catalysts For The Ternary Co-Polymerization Of Ethylene/Propylene/Norbornene

Ethylene propylene diene monomer（EPDM）is a high-end polyolefin material with unique chain structure that endows it with excellent performance.Compared with traditional ethylene propylene diene monomer（EPM）,EPDM has better performance and is widely used in the automotive industry,building materials,industrial rubber products,plastic modification,petroleum additives and other fields.China is the major consumer of ethylene propylene rubber in the groble.So mastering the production technology of EPDM is of great significance.It is worth noting that the preparation technology of high-end metallocene catalysts is one of the key core technologies.Because the characteristic of metallocene catalysts is that these catalysts have an efficient single active center,no need for deashing in the production process,high third monomer copolymerization content,and excellent product performance.Based on the new concept of active site regulation given by our research group,this topic introduced a strong electronic withdrawing group（for example-F）into the structure of metallocene complexes.We have designed and synthesized three new limited geometric configuration metallocene catalysts,and tested and analyzed the intermediates,ligands,and complexes using advanced methods such as ¹H-NMR,¹³C-NMR,GC-MS,and XPS.These results demonstrated the successful synthesis of three CGC metallocene catalysts Cat.A-Cat.C.Simulating the industrial production model of the monomers feeding,a series of polymerization experiments were carried out using the synthesized catalyst Cat.A-Cat.C activated by MAO under tamospheric pressure.According to the polymerization experimental results,under the optimus conditions:0.1 MPa of polymerization pressure,60℃of polymerization temperature and 300 of n（Al）/n（Ti）,Cat.C showes the highest activity of1.83×10⁵g/(mol _Ti·h)for ethylene homopolymerization,and a maximum catalytic activity of 0.67×10⁵g/(mol _Ti·h)for propylene homopolymerization.We also investigated the effects of ligand structure,polymerization temperature,n（Al）/n（Ti）,and feed ratio E/P on ethylene/propylene binary copolymerization.When the polymerization pressure is 0.1 MPa,the temperature is 60℃,n（Al）/n（Ti）is 300,and the feed ratio is E/P=3/7,Cat.C with difluoro substituents is the best catalyst for binary copolymerization.A binary copolymer with a propylene content of up to 40.12 mol%,a melting point of 115.27℃,and a crystallinity of 2.98%was synthesized using Cat.C.We also used 5-ethylene-2-norbornene（ENB）to copolymerize with ethylene and propylene.We synthesized a ternary copolymer（ENB-EPDM）with propylene content of 36.60 mol%and ENB content of 6.20 mol%under the polymerization conditions of 0.1 MPa,60℃,n（Al）/n（Ti）=300,E/P=3/7,and C_ENB=0.1 mol/L.Polymerization experiment results have shown that the content of propylene in the copolymer can be controlled by adjusting the feed of propylene,and ternary copolymers ENB-EPDM with different ENB contents can be synthesized by adjusting the feed of the third monomer（ENB）.Therefore,this work provides a new technology for synthesizing EPM and EPDM.