Premium
Semi‐Batch Polymerisation of Ethylene with Single‐Site Catalysts in the Presence of Hydrogen, 1. Modelling of Molecular Weight Distributions
Author(s) -
Blom Richard,
Dahl Ivar M.
Publication year - 2001
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20010301)202:5<719::aid-macp719>3.0.co;2-p
Subject(s) - hydrogen , catalysis , ethylene , polymerization , chemistry , molar mass distribution , reaction rate constant , polymer chemistry , chain transfer , chemical engineering , organic chemistry , kinetics , polymer , radical polymerization , physics , quantum mechanics , engineering
A modelling strategy is presented for prediction of molecular weight distribution (MWD) obtained by single‐site catalysts when polymerising ethylene in the presence of hydrogen as chain transfer agent. The different ways of hydrogen addition into the reactor are discussed: i) adding all hydrogen in one batch at the beginning of the polymerisation, ii) adding hydrogen at a constant flow rate throughout the polymerisation, and iii) adding hydrogen at a constant H 2 /ethylene ratio throughout the polymerisation. The shape of the MWD curves are strongly dependent on the way hydrogen has been introduced and on the ratio between the rate constant for termination by chain transfer to hydrogen and the propagation rate, k tH2 / k p , for the actual catalyst. The effects of catalyst deactivation and productivity are discussed as well.