Breaking Down the Building Blocks: Quantum Chemical Analysis of Diels–Alder Reactions for Future Self-Healing and Recyclable Polymer Networks

Covalent adaptable networks (CANs) are a key component for future development of sustainable materials. By modifying the Diels-Alder (DA) chemistry used as cross-links within these CANs, one can obtain polymers with tunable kinetic and thermodynamic properties. Given the large number of possible diene/dienophile combinations, computational chemistry presents itself as an ideal platform to study the full DA energetics. In this work, 130 DA reactions were scrutinized using density functional theory, with special attention for biobased components and endo/exo stereoisomerism. We found that the Diels-Alder reaction can be conditioned for a broad spectrum of applications, with bond formation and breaking at desired temperature ranges. Based on structural features and electronic nature, reactivity trends were studied to further enhance our understanding of the DA chemistry. Finally, for some interesting combinations, the kinetic and thermodynamic properties were translated to conversion curves. This work serves as a guide for the smart selection of suitable DA chemistry for sustainable material applications.