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Determination of the Catalytic Sites for Ziegler‐Natta Homo‐Polymerization from GPC Data
Author(s) -
Maddipati Sridhar V.,
Delgass W. Nicholas,
Caruthers James M.
Publication year - 2011
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.201000040
Subject(s) - natta , tikhonov regularization , deconvolution , polymerization , ziegler–natta catalyst , catalysis , a priori and a posteriori , polymer , polyethylene , polymer chemistry , regularization (linguistics) , distribution function , chemistry , materials science , thermodynamics , mathematics , inverse problem , algorithm , mathematical analysis , physics , computer science , organic chemistry , philosophy , epistemology , artificial intelligence
Deconvolution of the MWD of a polymer produced by multi‐site catalysts into independent Flory modes is the first step in modeling the polymerization process. A new deconvolution procedure for GPC data is developed that does not require an a priori assumption concerning the nature of the discrete distribution and can be used with a continuous distribution. The MWD measured via GPC is a linear function of the individual catalytic sites, but it is numerically ill‐conditioned, preventing direct inversion of the GPC data. Tikhonov regularization has been developed to uniquely invert the MWD. Applying the regularizing method to a polyethylene produced via a Ziegler‐Natta catalyst, seven discrete sites were found, and the kinetic constant ratios were determined for each of these sites.