Thiol–Anhydride Dynamic Reversible Networks. (1st April 2020)

• Record Type: Journal Article
• Authors: Podgórski, Maciej; Mavila, Sudheendran; Huang, Sijia; Spurgin, Nathan; Sinha, Jasmine; Bowman, Christopher N.
• Is Part Of: Angewandte Chemie. Volume 132:Number 24(2020)
• Page Start: 9431
• Page End: 9435
• Publication Date: 2020-04-01
• Subjects: covalent adaptable networks -- dynamic composites -- photopolymers -- recycling -- stress relaxation; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202001388
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The reaction of thiols and anhydrides to form ring opened thioester/acids is shown to be highly reversible and it is accordingly employed in the fabrication of covalent adaptable networks (CANs) that possess tunable dynamic covalent chemistry. Maleic, succinic, and phthalic anhydride derivatives were used as bifunctional reactants in systems with varied stoichiometries, catalyst, and loadings. Dynamic characteristics such as temperature‐dependent stress relaxation, direct reprocessing and recycling abilities of a range of thiol–anhydride elastomers, glasses, composites and photopolymers are discussed. Depending on the catalyst strength, 100 % of externally imposed stresses were relaxed in the order of minutes to 2 hours at mild temperatures (80–120 °C). Pristine properties of the original materials were recovered following up to five cycles of a hot‐press reprocessing technique (1 h/100 °C). Abstract : On the move : Thiol–anhydride networks were fabricated and assessed for their dynamic reversible characteristics. Three anhydrides (maleic, succinic, and phthalic) were used to create dynamic thermosets of diverse propensities for thioester anhydride link reversion. An impressive degree of control over their dynamic responsiveness was achieved.