Synthesis of half metallocene complexes ([O,N]CpTiCl 2) containing 8 hydroxy quinoline ligand is described.The results indicate that [O,N]CpTiCl 2 is active for ethylene polymerization at 30℃ and 0.1?mPa with MAO activation,and exhibits much higher activity than CpTiCl\-3.The results show that when there is an electron donor substituent next to N,such as a methyl,the activity of [O,N]CpTiCl 2 increases greatly; however,if there is an electron acceptor substituent,such as nitro in the benzene ring,it is inactive.For the [O,N]CpTiCl 2/MAO system,the polymerization rate is “up and down” type with increasing the Al/Ti molar ratio.The activity reaches its maximum at molar ratio of Al/Ti = 500,which is over 1×10 5?gPE/molTi·h.The activity decreases as the polymerization time is longer.The polyethylene obtained is characteristic of narrow molecular distribution with molecular weight M w around 40×10 4 and molecular weight ratio M w/ M n=2 8.
Synthesis and elemental analysis of metallocene analogic complexes (NpCpTiCl 2) containing the azole ligand (Np) are described,in which Np is Pr=Pyrolyl (C 4H 4N)(1); Id=Indolyl (C 8H 6N)(2); Ai=7 Azaindolyl (C 7H 5N 2)(3); Iz=Indazolyl (C 7H 5N 2)(4); Bi=Benzimidazolyl (C 7H 5N 2)(5),respectively.It is proved by the experiments that NpCpTiCl 2 is active for ethylene polymerization at 30℃ and 0.1?mPa with MAO activation,and the results show that the activity of 1 and 2 which contain one nitrogen in the azole ring is higher than 4 and 5 which contain two nitrogens,while 3 is inactive.For the NpCpTiCl 2/MAO system,the activity is “up and down” type with increase in the Al/Ti molar ratio,and up to the highest when the Al/Ti molar ratio is about 500.The polyethylene obtained is characteristic of narrow distribution with molecular weight M w around 35×10 4 and molecular weight ratio M w/ M n less than 3.
Ethyl ( iso butyl) aluminoxane(EBAO) was synthesized and characterized by UV Visible spectrum. The four absorption peaks of UV Visible spectrum of EBAO were assigned to the different sequence distributions of alkyl groups of EBAO. Ethylene copolymerization by Et(Ind) 2ZrCl 2/EBAO and MAO was investigated. The interaction between metallocene and aluminoxanes was monitored by UV Visible spectra. It was found that EBAO would form looser ion pair than MAO and accounted for the high comonomer incorporation of copolymers synthesized by EBAO.
