Study On Synthesis And Application Of The Internal Electron Donor 1,3-Dioldiether, Dibenzoylesters In Z-N Catalyst

The traditional catalyst used for polypropylene was Ziegler-Natta(Z-N) catalyst in industry. And the internal electron donor played an irreplaceable role in Z-N catalyst. 1,3-Diether and 1,3-diol ester, recently researched, were the novel internal electron donors. And a new generation of Z-N catalyst, which was synthesized with diether and diol ester, had high activity, orientability easily adjusted and high stereospecificity without any external donors.In this paper we studied the sythesis of 2,2-diisobutyl-1,3-propanediol dimethyl ether, which was a good example of 1,3-propanediol dimethyl ether of the internal electron donors. 2,2-Diisobutyl-1,3-propanediol dimethyl ether was synthesized from diethyl malonate and isobutyl bromide by alkylation, ester reduction and etherification. The key effects of reaction conditions were studied and the optimal results were gained. The overall yield of the desired product was 71.8% which was higher about 37.0% than the previously reported. The result of propylene polymerization showed that the catalytic activity, with 2,2-diisobutyl-1,3-propanediol dimethyl ether as the internal electron donors, was higher than with traditional dibutyl phthalate.Besides, The 1,3-propanediol dibenzoate derivatives, including 2,2-diisobutyl-1,3- propane- diol dibenzoate, 2,2-diisobutyl-1,3-propanediol di(p-chloro)benzoate, 2,2-diisobutyl-1,3-pro- panediol di(m-chloro)benzoate, 2,2-diisobutyl-1,3-propanediol di(o-chloro) benzoate, were synthesized from 2,2-diisobutyl-1,3-propanediol and corresponding benzoyl chloride by the esterification reaction. They had not been reported in literature, and their yield was over 90%. The result of propylene polymerization showed that the catalytic activity and stereospecificity, with 2,2-diisobutyl-1,3-propanediol dibenzoate derivatives as the internal electron donors, was both higher than with traditional dibutyl phthalate. And it significantly increased catalytic activity to introduce chloro group on benzene ring of 2,2-diisobutyl-1,3-propanediol dibenzoate while other properties unchanged, and when chloro located on the meta position to carboxylic group it worked best. And it proved that the substituent groups of 1,3-diol ester had an important impact on the catalyst performance. This provides a reference for the design of new ligand structures.