The main activity is focused on homo- and copolymerisation (random and sequential) of propylene with other 1-alkenes, both in hydrocarbon slurry and liquid propylene as well as in the gas phase. Computer controlled reactors with GC facility and a data processing system are available. Unique stainless-steel computer controlled bench reactors with GC facility and a data processing system are available. Sensitive flow controllers enable continuous feeding of monomer, co-monomer, and hydrogen and secure their constant concentrations throughout polymerisation run. Two reactors are equipped with static sensors and the static charge in polymer bed can be monitored.
Synthesised polymers may be studied from the viewpoint of their structure and physico-mechanical properties. The following parameters can be determined:
- melt flow rate, soluble fractions, extractable fractions, density, particle size distribution, bulk density, morphology, porosity and bulk properties of polymer powder
- structure characterisation by means of DSC, 1H- and 13C-NMR and pulsed 1H-NMR, GPC, FTIR, SSA/DSC, SIS/DSC, TREF, VOC and other methods
- tensile strength, toughness, hardness, heat resistance
Examples of activities:
- assessment of structure and properties of materials based on polypropylene
- examination of the influence of specific impurities in raw materials upon the kinetics of the process and the polymer properties
- polymerisation and analytical evaluation of raw materials used for industrial olefin polymerisation
- fine purification of raw materials to polymerisation purity (down to a level below 10 ppb of the most critical impurities)
- development of catalyst systems based on commercial catalysts to fit the industrial process
- cooperation with major world producers of catalysts for olefin polymerisation both on a contract and non-commercial basis
- theoretical studies of polymerisation kinetics (including determination of concentration of active centres) in cooperation with a number of universities and academic institutions at home and abroad
- development of new or modified PP grades (homopolymers, random and sequential copolymers)
- static charge monitoring and control for a specific polymerisation system
Software Homopolymerisation model
We have created new software called “Homopolymerisation model” in the Polypropylene synthesis department. This software has been developed in the scope of research & development innovative program TIP of Ministry of Industry and Trade of the Czech Republic in the project FR-TI1/140 called "Synthesis of new polypropylene grades based on reactor modelling of polymerisation process".
This software enables modelling of laboratory two-steps homopolymeriastion process and polymer properties of resulting homopolymer grades. As it is depicted in the window of this software at the enclosed figure, we can calculate on the basis of the input data (which are polymerisation temperature at both polymerisation steps, concentration of hydrogen at both polymerisation steps, time duration of both polymerisation steps) the following results and dependencies:
polymerisation kinetics patterns and corresponding polymerisation yields,
molecular weight distribution (MWD) curves of polymer (corresponding to homopolymers of particular polymerisation steps and of the whole polymerisation),
values of molecular weights Mn, Mw, Mz and broadness of distribution Mw/Mn (corresponding to homopolymers of particular polymerisation steps and of the whole polymerisation),
melt flow rate (M.F.R., corresponding to homopolymers of particular polymerisation steps and of the whole polymerisation).
Interested persons can contact:
Mgr. Jan Grůza, Ph.D.
The Stopped-Flow facility for 1-alkene polymerisation
The high pressure Stopped-Flow apparatus was constructed for synthesis of maximal yield of a special type copolymer of polypropene-block-poly(propene-co-ethene) structure. The polymerisation is performed in liquid propene monomer. The stopped-flow polymerisation is performed in the glass tube. Two catalyst system components with monomer(s) are efficiently mixed in the in a special mixing zone and flow through the polymerisation zone into the flask containing a quenching agent. This technique allows performing polymerisation experiments shorter than average lifetime of the growing polymer chains (several tens of second). The Stopped-Flow apparatus enables investigation of the catalyst performance during the early (<1 s) stages of polymerisation. Successful preparation of block copolymers provides a new insight into the nature of active sites present in polymerisation catalysts and also allows to investigate the role of block copolymers in heterogeneous materials consisting of crystalline matrix (polypropene) with inclusions of amorphous poly(ethene-co-propene) rubber (impact resistant sequential copolymers produced by industrial two-reactor technology).