Polysquaramides.

Thermoplastics, while advantageous for their processability and recyclability, often compromise thermochemical stability and mechanical strength compared to thermosets. Addressing this limitation, we introduce an innovative approach employing reversibly cross-linked polymers, utilizing squaramide moieties to reconcile recyclability and robustness. Herein, we detail the synthesis of supramolecularly cross-linked polysquaramides through the condensation polymerization of diethyl squarate with primary and secondary diamines.

High-performance polyimine vitrimers from an aromatic bio-based scaffold.

Bio-based vitrimers represent a promising class of thermosetting polymer materials, pairing the recyclability of dynamic covalent networks with the renewability of non-fossil fuel feedstocks. Vanillin, a low-cost lignin derivative, enables facile construction of polyimine networks marked by rapid exchange and sensitivity to acid-catalyzed hydrolysis. Furthermore, the aromatic structure makes it a promising candidate for the design of highly aromatic networks capable of high-performance thermal and dimensional stability.

Dynamic Ablative Networks: Shapeable Heat-Shielding Materials.

Thermoset materials sacrifice recyclability and reshapeability for increased chemical and mechanical robustness because of an immobilized, cross-linked polymeric matrix. The robust material properties of thermosets make them well-suited for applications such as heat-shielding materials (HSMs) or ablatives where excellent thermal stability, good mechanical strength, and high charring ability are paramount. Many of these material properties are characteristic of covalent adaptable networks (CANs), where the static connectivity of thermosets has been replaced with dynamic cross-links.