Effects of diethyl aluminum chloride (DEAC) addition to the catalysts prepared by reduction of TiCl4 with EtMgCl on ethylene-propylene copolymerization
✍ Scribed by Kyung-Jun Chu; Ho-Sik Chang; Son-Ki Ihm
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 471 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0014-3057
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✦ Synopsis
TiClfl2.5MgC12(O.5MgEtz
)/THF catalyst (R) was prepared by the reduction of TiCI 4 with EtMgC1. The effect of diethyl aluminum chloride (DEAC) addition on the catalytic activity in ethylene-propylene copolymerization was investigated. It was suggested from FT-i.r. that the catalyst R formed similar bimetallic (Ti-Mg-THF) complexes to the TiC13(AA)/3MgC12/THF catalyst (T3ME) of our previous report . An ESR study provided evidence that the Ti 3+ species in the catalyst R was of the multinuclear type, instead of an isolated type of T3ME, and it changed from a tetrahedral to an octahedral structure with addition of DEAC. The activities of R catalysts in copolymerization were more or less in the same order of magnitude with each other due to the multinuclear nature of the Ti 3+ species, and the response to propylene comonomer decreased with addition of DEAC. The polydispersity of comonomer over R catalysts was in the range of 6-10, being much broader than that over the T3ME catalyst system. It might be due to the heterogeneity of the titanium(Ill) structure; tetrahedral as well as octahedral in R, instead of only octahedral in T3ME.