Rheological and chemical analysis of reverse gelation in a covalently cross-linked diels-alder polymer network

Brian J. Adzima, H. Alan Aguirre, Christopher J. Kloxin, Timothy F. Scott, Christopher N. Bowman

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196 Citations (Scopus)

Abstract

A network polymer, incorporating dynamic and reversible cross-links, was synthesized using the Diels-Alder reaction. Fourier transform infrared (FTIR) spectroscopy was used to characterize the reaction rate and thermodynamic equilibrium over a broad temperature range. Equilibrium conversion of the furan and maleimide varied from 74% at 85 °C to 24% at 155 °C. demonstrating significant depolymerization via the retro-Diels-Alder reaction. The gel point temperature, as determined by rheometry using the Winter-Chambón criterion, was 92°C. corresponding to a gel-point conversion of 71%, consistent with the Flory-Stockmayer equation. The scaling exponents for the complex moduli, viscosity, and plateau modulus, in the vicinity of the gel-point, were determined and compared with experimental and theoretical literature values. Further, the material exhibited a low frequency relaxation owing to dynamic rearrangement of cross-links by the Diels-Alder and retro-Diels-Alder reactions.

Original languageEnglish
Pages (from-to)9112-9117
Number of pages6
JournalMacromolecules
Volume41
Issue number23
DOIs
Publication statusPublished - 9 Dec 2008
Externally publishedYes

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