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Updated: Jun 10, 2026

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry
Published on: August 25, 2016
Rheological and chemical analysis of reverse gelation in a covalently crosslinked Diels-Alder polymer network
Brian J Adzima1, H Alan Aguirre, Christopher J Kloxin
1Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309-0424, USA.
Abstract:
A network polymer, incorporating dynamic and reversible crosslinks, 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-Chambon 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 crosslinks by the Diels-Alder and retro-Diels-Alder reactions.
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