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Calculations of Monomer Conversion and Radical Concentration in Reversible Addition-Fragmentation Chain Transfer Radical Polymerization

Authors

  • Aileen R. Wang,

    1. Department of Chemical Engineering, McMaster University, Hamilton, Ontario, L8S 4L7, Canada
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  • Shiping Zhu

    Corresponding author
    1. Department of Chemical Engineering, McMaster University, Hamilton, Ontario, L8S 4L7, Canada
    2. Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, L8S 4L7, Canada
    • Department of Chemical Engineering, McMaster University, Hamilton, Ontario, L8S 4L7, Canada. Fax: +1 905 521 1350
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Abstract

Simple expressions are derived for the development of monomer conversion, as well as propagating radical, adduct radical, dormant chain, and dead chain concentrations in reverse addition-fragmentation transfer polymerization (RAFT). The relations for the profiles of propagating radical concentration and conversion versus time are derived and depend on group parameters of rate constants and chemical recipe. The analytical equations are verified against numerical solutions of the mass-balance differential equations. This derivation involves the steady-state hypothesis for radical and RAFT agent concentrations. The errors introduced by these assumptions are negligible when the fragmentation rate constant, kf, is higher than 10 s−1 or when the cross-termination rate constant, kct, is higher than 105 L · mol−1 s−1.

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Calculated concentration profiles (points: numerical, lines: analytical) of propagating radical R, adduct radical A, dormant T, and dead D (= P + P′) chains.

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