The primary objectives of this effort were to develop dynamic covalent crosslinked polymers with dynamic self-healing capabilities by functionalizing acrylate- and polyurethane-based resins and demonstrate their feasibility as robust isocyanate free coating systems with self-healing capability.

It was hypothesized that dynamic isocyanate-free polymers with properties comparable to current military coatings can be generated leveraging thermoreversible Diels-Alder (DA) chemistry. Monomers were modified with DA moieties to produce polymer resins, from which films were prepared to evaluate solvent resistance, melt processing, and comparison to current military specifications.

In this project, the team successfully designed, synthesized, and evaluated a dynamic covalent polymer network composed of DA modified-monomers derived from conventional polyurethane coating feedstocks that demonstrated excellent solvent stability and melt processability.

These materials have potential to serve as a foundation for the development of a new class of dynamic coatings and polymers with thermoset characteristics at ambient temperatures and thermoplastic processability at elevated temperatures, such as self-healing and removable thermosets, to next-generation adhesives, and recyclable thermoset polymer-based materials.