| The scientific research on Ziegler-Natta catalysis for the development of polyolefin has a very far-reaching significance. The third component play an important role in Ziegler-Natta catalyst. Study and explore on the novel electron donor has become a hotspots of the polyolefin industry. This paper presented some Ziegler-Natta catalysts which include new ether electron donor (ED1-ED5). We compared the catalyst which include ED1-ED5 in the ethylene polymerization, and the triethoxy methane amount were also studied. We studied the effect mix of Si(OEt)4, tributyl phosphate or tributyl borate with triethoxy methane on the preparation of catalyst, and the dropping temperature and amount of TiCl4 were also discussed. The amount of titanium loading, the crystalline properties,the morphology of catalyst and the oxidation state of titanium were characterized by ICP, WAXD, SEM and XPS. The results showed the triethoxy methane as a inter electron donor had a best properties. When the n(ED)/n(MgCl2) was 0.20, the volume of TiCl4 was 20ml and the dropping temperature of TiCl4 was -10?, we got the optimum preparation of catalyst. From the results of particle size analysis and SEM, we could be drawn the prepared catalyst had a uniform particle size distribution and was spherical. From the result of WAXD of Cat4, we found the a-MgCl2 transform to ?-MgCl2.We also focused on the effects of mole ratio of Al/Ti and polymerization temperature Tp, and the high pressure on the ethylene polymerization when we used the Cat4. The results showed the Cat4 had the best performance when the mole ratio of Al/Ti is 100:1 and the polymerization temperature Tp is 80?. From the analysis of FT-IR, SEM, DSC, WAXD, TG results, we could obtained the PE was a linear molecular structure, the morphology of polyethylene was spherical on the surface and the crystallinity of polyethylene was 78.05%.The decomposition temperature was high and the residual ash content was low after the decomposition. |
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