Direct synthesis of linear low density polyethylene of ethylene/1-hexene directly from ethylene using tandem catalytic system in single reactor
作者：F. AlObaidi, Z. Ye, S. Zhu*
關鍵字：無
論文來源：期刊
具體來源：Journal of Polymer Science, Part A, Polymer Chemistry
發(fā)表時間：2004年
Tandem catalysis offers a promising synthetic route to the production of linear low‐density polyethylene. This article reports the use of homogeneous tandem catalytic systems for the synthesis of ethylene/1‐hexene copolymers from ethylene stock as the sole monomer. The reported catalytic systems employ the tandem action between an ethylene trimerization catalyst, (η5‐C5H4CMe2C6H5)TiCl3 (1)/modified methylaluminoxane (MMAO), and a copolymerization metallocene catalyst, [(η5‐C5Me4)SiMe2(tBuN)]TiCl2 (2)/MMAO or rac‐Me2Si(2‐MeBenz[e]Ind)2ZrCl2 (3)/MMAO. During the reaction, 1/MMAO in situ generates 1‐hexene with high activity and high selectivity, and simultaneously 2/MMAO or 3/MMAO copolymerizes ethylene with the produced 1‐hexene to generate butyl‐branched polyethylene. We have demonstrated that, by the simple manipulation of the catalyst molar ratio and polymerization conditions, a series of branched polyethylenes with melting temperatures of 60–128 °C, crystallinities of 5.4–53%, and hexene percentages of 0.3–14.2 can be efficiently produced.