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Hyperbranched Polymers Formed through Irreversible Step Polymerization of AB 2 ‐Type Monomer in a Continuous Flow Stirred‐Tank Reactor (CSTR)
Author(s) -
Tobita Hidetaka
Publication year - 2017
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.201600078
Subject(s) - continuous stirred tank reactor , radius of gyration , polymerization , polymer , branching (polymer chemistry) , polymer chemistry , monomer , chemistry , molar mass distribution , degree of polymerization , materials science , thermodynamics , organic chemistry , physics
Hyperbranched polymers formed through step polymerization of AB 2 ‐type monomer with equal reactivity for both B groups in a continuous flow stirred‐tank reactor (CSTR) are investigated theoretically. The weight fraction distribution at high molecular weight tail follows a power law, W ( P ) ∝ P −1/ξ for ξ ≤ 0.5 with ξ = k [ A ] 0 t ¯ , where t ¯ is the mean residence time. The degree of branching (DB) at the large degree of polymerization ( P ) limit is DB P →∞ = 0.6 irrespective of the ξ‐value, which is larger than the case for the corresponding batch polymerization that gives DB P →∞ = 0.5. The relationship between the radius of gyration 〈 s 2 〉 0 and P shows that the hyperbranched polymers formed in a CSTR are very compact, and the 〈 s 2 〉 0 ‐values for large polymers are even smaller than the smallest possible case for a batch reactor with DB P →∞ = 1. For large polymers, the power law 〈 s 2 〉 0 ∝ P 1/3 holds, which is 〈 s 2 〉 0 ∝ P 1/2 for batch polymerization.