Polymerization of styrene to isotactic polymer with MAO-Ni(acac)2. Examination of the factors that influence activity and stereospecificity
✍ Scribed by Geraldo Lopes Crossetti; Carlotta Bormioli; Alberto Ripa; Antonino Giarrusso; Lido Porri
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 347 KB
- Volume
- 18
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
The soluble catalyst system methylaluminoxane (MAO)‐Ni(acac), (acac: acetylacetonate) gives polystyrene consisting of an amorphous (aPS) and a crystalline isotactic (ips) fraction. Al(CH~3~)~3~, which is always present in commercial samples of MAO, decreases both polymer yield and stereospecificity. The polymer yield increases with increasing the MAO/Ni ratio but, at the same time, the iPS/aPS ratio decreases. Addition of N(C~2~H~5~)~3~ (mole ratio N/Ni = 1) increases the proportion of the isotactic fraction, while it decreases the polymer yield. A tentative interpretation of the stereospecificity is reported.