Synthesis of Novel Bis(β‐enaminoketonato)titanium Catalyst with High Activity and Excellent Ability to Copolymerize Olefins

Abstract

A new titanium complex [PhN=C(Ph)CHC(CF3)O]2TiCl2 (2a), with an asymmetric β‐enaminoketonato [N,O] ligand, has been synthesized and fully characterized. With modified methylaluminoxane as a cocatalyst, the behaviors of ethylene polymerization, and ethylene/α‐olefin and ethylene/norbornene copolymerization have been explored in detail. Relative to its regioisomer 2b ([PhN=C(CF3)CHC(Ph)O]2TiCl2), the present catalyst exhibits significant predominance. The catalytic activity in 2a‐catalyzed homo‐ and copolymerization are much higher than those in 2b‐catalyzed (co)polymerization. Furthermore, compared with 2b, catalyst 2a possesses an obviously stronger ability towards copolymerization, due to a wide coordination space caused by exchanging the position of the phenyl group and trifluoromethyl group on the framework.

The Influence of Ziegler-Natta and Metallocene Catalysts on Polyolefin Structure, Properties, and Processing Ability

“…Studies by Ronkko and co-workers [ 74 ] reveal that polymerization and fragmentation behavior of catalysts is dependent on the type of catalyst and nature of the catalyst support [ 75 , 76 ]. The catalyst should have (i) high porosity to allow good reactant diffusion; (ii) high mechanical strength to withstand thermal or chemical shocks while simultaneously possessing the ability to break up during polymerization; (iii) the ability to undergo fragmentation to yield desirable polymer content without having large contaminated fragments in the final product; and (iv) a decent distribution of active sites to ensure an even allotment of the final polymer product [ 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 ].…”

Copolymerization of Ethylene and 1‐Hexene with Ansa‐Dimethylsilylene(fluorenyl) (t‐butylamido)Dimethyltitanium Complexes Activated by Modified Methylaluminoxane

“…Table summarizes the monomer reactivity ratios in ethylene/1‐hexene copolymerization with representative single‐site catalysts reported so far. The monomer reactivity ratios of 1 and 2 are comparable to those of a typical CGC and half‐titanocene catalysts, which are superior to those of metallocene catalysts . We have reported that complex 2 can promote random copolymerization of 1‐alkene and norbornene with high activity .…”

Kinetics, Mechanism and Theoretical Studies of Norbornene-Ethylene Alternating Copolymerization Catalyzed by Organopalladium(II) Complexes Bearing Hemilabile α-Amino–pyridine

“…Cyclic olefin copolymers (COC) have demonstrated wide-range applications in the industries of coating, packaging, medical equipment, etc. [ 1 , 2 , 3 , 4 , 5 , 6 ], because of their high T g , high transparency, low dielectric constants, and good biocompatibility and processability [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. These physical properties are usually controlled by the compositions and the microstructures of the monomers, resulting from the design of the catalysts [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ].…”