Synthesis Of Novel Titanium Catalysts And Catalyzation For Olefin (Co) Polymerization

In our world today, polyolefin is the largest product of syntheticresin and the most widely used polymer materials, while the catalyst isthe key and heart of the polyolefin industrial development. In recent years,traditional Ziegler-Natta catalyst gets flying development and thehomemade-percentage reached90%. In the same time, the breakthroughin metallocene catalysts and late transition metal catalysts extended theresearch field of olefin polymerization. As the sustainable development ofthe national economy, the demand for polyolefin resin grows rapidly andthe domestic production （Most of products are low-added-value） can onlymeet about half of the domestic demand. In addition, R&D andindustrialization of Chinese polyolefin field started very late, about10years after the USA, Europe and Japan. And our technical basis stillappears very fragile, then, the development of high-performance productis fairly weak. The core polyolefin technologies with self-ownedintellectual property are a serious short, therefore, urgently need toconduct an in-depth research and development.Currently, in order to overcome the shortage of low-add-value ofcatalyst and the short supply of high-performance product, our country’s polyolefin catalyst research concentrated on produce higher catalystactivity and higher stereoselective catalyst.After consult a lot of references, this paper synthesized a noveltitanium-based catalyst, and the olefin （co-）polymerization behaviors ofthe obtained catalyst were studied in detail. This thesis sections asfollowing:1. A novel Ziegler-Natta catalyst has been prepared throughintroducing electron withdrawing ligand to traditional Ziegler-Nattacatalyst. Polymerization behaviors of the novel catalyst have beeninvestigated for ethylene polymerization ethylene and ethylene-norborenecopolymerization. The catalyst and polymer composition, polymermolecular weight and thermal properties were investigated by elementanalysis, XPS, DSC,¹H-NMR, FTIR, GPC, TGA and so on. It has beenfound that the catalytic activity of novel catalyst is much higher than thatof the corresponding traditional Ziegler-Natta catalyst toward ethylenepolymerization and ethylene-norborene copolymerization. Regarding toethylene-norborene copolymerization, the incorporation ability of novelcatalyst is similar to traditional Ziegler-Natta catalyst.2. The ethylene polymerization and ethylene-norborenecopolymerization was carried out by using bisphenol-A or PhSO-3ligandmodified Cp*TiCl3catalyst. The effect of ligand feed ratio,polymerization conditions on polymerization behaviors were studied. Thepolymer composition, polymer molecular weight and thermal propertieswere investigated by DSC,¹³C-NMR, GPC, TGA and so on. It was foundthat the catalytic activity of bisphenol-A or PhSO-3ligand modifiedCpTiCl3catalyst is higher than that of the Cp*TiCl3catalyst towardethylene polymerization and ethylene-norborene copolymerization. TheGPC curve of obtained ethylene-norborene copolymer is unimodal andthe thermal properties of the copolymer is higher than polyethylene. However, with regard to the ethylene-norborene copolymerization, theincorporation ability of novel catalyst was less changed.3. A novel TiCl4complex ligated by diphenylphosphinobenzenesulfonic acid was synthesized and the structure was confirmed by elementanalysis,^<sup>1H-NMR,31P-NMR and SEM. After that, the ethylenepolymerization and ethylene-norborene copolymerization was carried outby using the obtained catalyst in conjunction with MAO or TEA ascocatalyst. The ethylene-norborene copolymerization is additionpolymerization. The effect of polymerization conditions onpolymerization behaviors and polymer properties were characterized by¹³C-NMR, DSC, GPC. It was found that the catalyst with MAO ascocatalyst performed with a higher activity toward ethylene（co）polymerization than that with TEA as cocatalyst. The catalyticactivity increased with increasing Al/Ti ratio. In the same time, thepolymer properties （e.g. melting temperature, molecular weight and itsdistribution） was influenced by polymerization temperature, pressure andcomonomer feed ratio. Therefore, the polymer properties could becontrolled through changing polymerization parameters.Although the catalyst activity, norborene incorporation rate wasimproved, compared with the before mentioned catalyst, but, the catalystperformance are still fairly low and the incorporation ability need futuredevelopment.4. A novel titanium complex bearing8-anilino-1-naphthalenesulfonic acid was synthesized and the structurewas confirmed by element analysis,^<sup>1H-NMR,¹³C-NMR, H-H COSY,SEM and MALDI-TOF MS. The ethylene polymerization andethylene-norborene copolymerization was carried out by using theobtained catalyst in conjunction with MAO or TEA as cocatalyst. Theeffect of reaction parameters on polymerization behaviors and polymer properties was studied by¹³C-NMR, DSC and GPC. It was found that thesynthesized titanium complex/MAO catalyst system showed a uniformactive site and was very stable at high polymerization temperature. Thetitanium complex with MAO as cocatalyst performed with a highercatalyst activity toward ethylene polymerization and ethylene-norborenecopolymerization than that with TEA as cocatalyst and the catalyticactivity increased gradually with the Al/Ti ratio increased. Additionally,the novel catalyst shows very good copolymerization ability, theincorporation rate significantly improved compared with the catalyst usedin before. Narrow MWD and low Mw were observed with MAO ascocatalyst, but broad MWD and high Mw were observed with TEA ascocatalyst.In the same time, the polymer properties （e.g. melting temperature,molecular weight and norborene content） was influenced bypolymerization temperature, pressure, cocatalyst type and comonomerfeed ratio. Therefore, the polymer properties could be controlled throughchanging polymerization parameters. The ethylene-norborenecopolymerization is addition polymerization.