Kinetic Monte Carlo Generation of Complete Electron Spray Ionization Mass Spectra for Acrylate Macromonomer Synthesis

Paul H.M. Van Steenberge, Joke Vandenbergh, Marie Françoise Reyniers, Thomas Junkers, Dagmar R. D’hooge, Guy B. Marin

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23 Citations (Scopus)

Abstract

Absolute electron spray ionization mass spectrometry (ESI-MS) data are reported, for the first time, over the complete chain length range for the synthesis of well-defined macromonomers (MMs) obtained via activation of bromine-capped poly(n-butyl acrylate) (0.1 mass %; solvent: anisole; 140 °C) with CuBr2/Me6TREN (Me6TREN: tris(2-(dimethylamino)ethyl)amine) and tin ethylhexanoate. These data are generated based on bivariate kinetic Monte Carlo simulations, tracking the chain lengths and the positions of radicals/characteristic groups along the chains (>100 reactions, 12 radical/dormant species types, and 7 characteristic end/mid-groups). Based on qualitative tuning to experimental data, migration is found to be 50 times slower than backbiting but 15 times faster than βC-scission, making it a dominant reaction. Benefiting from the absence of monomer, the chain transfer to polymer rate coefficient is assessed as 6 × 102 L mol-1 s-1 (140 °C). Model analysis shows that consecutive backbiting/migration/βC-scission leads to a favoring of MMs with even chain lengths and a hydrogen chain end over MMs with the nonreactive chain end originating from the initial dormant polymer. The obtained insights contribute to a better fundamental understanding of hydrogen abstractions in acrylate radical polymerization and open the path for a more detailed polymer product characterization in general.

Original languageEnglish
Pages (from-to)2625-2636
Number of pages12
JournalMacromolecules
Volume50
Issue number7
DOIs
Publication statusPublished - 11 Apr 2017
Externally publishedYes

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