Comparison of Ethylene Copolymerization with Norbornene and 5-Norbornene-2-methanol by Using Ph2C(Cp)(Flu)ZrCl2/MAO

Both cyclic olefin copolymer (COC) and functionalized polyolefins are high-performance polyolefin materials with different outstanding properties. The introduction of functional groups into COC has the potential to yield materials that combine the advantages of both. In this work, ethylene copolymers with norbornene (NBE) or 5-norbornene-2-methanol (NBMO) are synthesized by using a metallocene catalyst. The activity and the molecular weight of copolymer of the former is much higher than that of the latter. A joint deactivation-chain transfer mechanism is proposed to interpret these observations. Chain transfer is further discussed. Through regression analysis, it is considered that the chain transfer mode of the two comonomers is the same. Three methods for the calculation of NBMO incorporation are proposed and compared, and a more suitable method is obtained, on the basis of the resonance assignment. The comparison of the copolymerization of ethylene with NBE and NBMO may indicate that NBMO has a higher coordination probability but a slower insertion rate compared to NBE.