Metallocene-Catalyzed Polymerization of Propylene to Highly Isotactic Polypropylene in Organic Suspension

Metallocene-Catalyzed Polymerization of Propylene to Highly Isotactic Polypropylene in Organic Suspension 

Safety precautions Before this experiment is carried out, Sect. 2.2.5 must be read as weii as the materiai safety data sheets (MSDS) for aii chemicais and products used. 

Couf/on. Refiuxing of toiuene over sodium/potassium aiioy must be done under permanent supervision. 

Highiy dried toiuene is the most usefui reaction medium.lt is obtained according to the foiiowing procedure. Pre-dried toiuene (over moiecuiar sieve) is refluxed over a iiquid sodium/potassium aiioy (5-10 mi for 2 i of toluene) for 4-5 days. An alternative method is the addition of n-butyllithium in small portions (ca.10 ml for 21 toluene) which can be visualized with benzophenone as indicator. When the toluene is sufficiently dried (change of color) it is distilled off and stored under argon (The used syringes or pipettes have to be flushed prior to use with argon after use they have to be cleaned immediately with toluene). 

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