================ Metallocene CSTR ================ .. |calculate| image:: /gui_icons/icons8-abacus.png :width: 20pt :height: 20pt :align: bottom .. contents:: Contents :local: Reaction theory --------------- The multiple metallocene CSTR reaction theory uses an algorithm based on the reaction scheme given by Read and Soares :cite:`m-Read2003`. That paper presented some analytical and semi-analytical derivations of molecular weight distributions for the case of two metallocene catalysts. The present algorithm is a Monte Carlo algorithm for simulating the case multiple catalysts. Note that some catalysts behave non-ideally, giving broad molecular weight distributions. These will need to be modelled as a combination of several catalysts with different rate parameters. Simulation parameters --------------------- On opening the theory, one is presented with (apparently) only four parameters, which are: .. include:: simulation_parameters.rst The remaining parameters are shown when you press the |calculate| button, which opens a form looking like: .. image:: images/metalloceneCSTR_form.png :width: 400pt :align: center :alt: metalloceneCSTR_form Here, one can set the total number of catalyst sites to be used in the calculation, the reactor time constant (the mean residence time in the CSTR), and the reactor monomer concentration. Then, for each catalyst site, there are five parameters to be fixed, as described in :cite:`m-Read2003`: * The active catalyst site concentration (if catalyst deactivation is significant, one should account for this by reducing this parameter). * The polymerisation rate constant, :math:`K_\text{p}`. * The rate constant for chain transfer to macromonomer, :math:`K^=`. Some chain transfer reactions result in the creation of a macromonomer, which can then subsequently be incorporated into a growing chain, forming a long-chain-branch. This chain transfer rate constant describes a reaction of form .. math:: P\rightarrow D^{=}+C, where :math:`P` is a macromonomer and :math:`C` is a free catalyst site (or short growing chain). Thus, :math:`K^=` is the total rate constant for all such processes, and the concentration of any chain transfer agents should be included within this rate constant. * The rate constant for chain transfer to dead chains, :math:`K^\text{s}`. Some chain transfer reactions result in the creation of a dead chain, which plays no further part in the reaction. Similar comments apply as for the constant :math:`K^=` * The polymerisation rate constant for incorporation of macromonomers to form long-chain-branches, :math:`K_\text{p,LCB}`. .. include:: gfactor_BoB_polymer_storage_and_memory.rst .. rubric:: References .. bibliography:: ../bibliography.bib :style: unsrt :keyprefix: m-