Comparison of olefin polymerization processes with metallocene catalysts

Solution and gas phase processes of the polymerization of ethene are compared using new types of pentalenyl bridged ansa-metallocenes such as [Me(3)Pen(Flu)]ZrCl2. As of the bridge, the catalyst system is remarkable thermostable up to 105 degrees C and a deactivation of the metallocene on the silica support can be suppressed. Compared to the non-supported catalyst in a solution process, the application of the heterogenized system in a gas phase process leads to a decrease in activities while molar masses of the polyethenes are similar. Due to a higher degree of short chain branches of 20-30 per 1 000 carbon atoms instead of 10-17, the melting temperatures are 10 degrees C lower than those for polymers obtained in the solution process.