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High impact polypropylene - kinetics and selectivity effects

Poster presented at 12th International Workshop on Polymer Reaction Engineering, 17. - 20. Mai 2016, University of Hamburg, Germany
: Drawpateep, Arkom; Bartke, Michael

2016, 1 Folie
International Workshop on Polymer Reaction Engineering <12, 2016, Hamburg>
Fraunhofer IAP ()
polymerization; propene; kinetics; heterophasic copolymers
Anfrage beim Institut / Available on request from the institute

High impact polypropylene is heterophasic polypropylene materials consisting of a homo-or random copolymer matrix and an elastomeric phase of propylene/ethylene copolymer, which is not miscible with the matrix phase. The elastomeric phase helps to improve impact strength, and extend its application at low temperature conditions. Polymerization of high impact polypropylene could be achieved by at least two stage processes. First the homo- or random copolymer matrix is produced in bulk or gas phase polymerization, and later on the elastomeric phase of propylene/ethylene copolymer is formed through polymerization in gas phase. Among several commercial process technologies available, Spheripol process (bulk homo- and gas copolymerization) is one of the most widely used process to produce high impact polypropylene globally. For target oriented product development, detailed knowledge of catalyst kinetics is necessary in order to establish the required operation conditions for the desired polymer characteristics. Kinetics of bulk polymerization of the propylene matrix polymer are investigated in our group by reaction calorimetry. With reaction calorimetry, the heat of reaction, which is proportional to the reaction rate, can be measured and used for development of kinetic models. The elastomeric ethylene propylene copolymer is produced by gas phase polymerization in semi-batch mode: The gaseous monomers are fed by mass-flow controllers to the reactor that way, that both pressure and gas composition, which is online monitored via a fast response micro-gas chromatography, stay constant. If temperature, pressure and composition are constant, the feed of monomers equals the individual reaction rates of both monomers. These kinetic experiments are carried out at industrial relevant operating conditions and the general activity-level is in comparable to larger scale operation. For two-stage bulk-gas phase experiments, a 5 liters reactor setup is available at Martin Luther University.