Catalyzed Polymerization of Propylene to Highly Isotactic Polypropylene in Organic Suspension

Example 3,32 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 well as the material safety data sheets (MSDS) for all chemicals and products used. 

Caution Refluxing of toluene over sodium/potassium alloy must be done under permanent supervision. 

Highly dried toluene is the most useful reaction medium. It is obtained according to the following procedure. Pre-dried toluene (over molecular sieve) is refluxed over a liquid sodium/potassium alloy (5-10 ml for 2 1 of toluene) for 4-5 days. An alternative method is the addition of n-butyllithium in small portions (ca. 10 ml for 2 1 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 

Caution Working with MAO has to be done under rigorous safety precautions Wearing of safety goggles and protective gloves is a must. MAO is highly reactive It reacts with moisture traces on the skin. If MAO is spilled, the contaminated area has to be covered with sand to prevent a fire. Then, MAO is hydrolyzed by the careful addition of 2-propanol or ethanol, followed by water (see also Example 3.28). 

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