Probabilistic multi-site modelling of propene polymerization using markov models

✍ Scribed by van der Burg, Marijke W. ;Chadwick, John C. ;Sudmeijer, Olof ;Tulleken, Herbert J. A. F.

• Book ID: 102944655
• Publisher: Wiley (John Wiley & Sons)
• Year: 1993
• Weight: 905 KB
• Volume: 2
• Category: Article
• ISSN: 1018-5054
• DOI: 10.1002/mats.1993.040020310

✦ Synopsis

Abstract

Possible propagation mechanisms in propene polymerization using heterogeneous catalysts are described by combinations of Bernoulli and first‐ or even second‐order Markov models. Both NMR‐measured pentad fractions and GPC Gel permeation chromatography.

‐measured molecular weight distributions are directly taken into account to fit an appropriate propagation model for a specific catalyst. The analytical data so obtained have been used for an examination of the applicability of multi‐site propagation models and for estimation of the main parameters in each model. The propagation and termination probabilities are estimated, as are “mix” parameters giving the fraction of the polymer population stemming from each kind of propagation mechanism. In this way the subpopulation produced by each site is characterized in terms of tacticity and molecular weight distribution. A three‐site model is required to explain the measured data properly.