Solution-Phase Synthesis of 2-D Polymers for Ultra-Lightweight, High-Strength Materials

Polymers that extend covalently in two dimensions have been conceptualized for more than 85 years but their synthesis has remained elusive. They promise a unique combination of the high mechanical strength of layered materials such as graphene but with the low densities, synthetic processability, and control of composition of one-dimensional polymers. The Strano research group previously demonstrated the first synthetic route to 2-D irreversible polycondensation directly in the solution phase, resulting in covalently bonded 2-D polymer platelets that are chemically stable and highly processable. Results have been published in the journal Nature. Collaborators from DEVCOM ARL have used molecular simulation to demonstrate that such new materials can achieve previously unattainable levels of mechanical strength per mass and area, and are highly promising for warfighter protection. Solution processing at preparative scales that has already been achieved enables highly oriented, large area free-standing films which exhibit exceptional 2-D elastic modulus and yield strength already exceeding 50 GPa and 1.0 GPa, respectively. This ISN-5 project will elucidate the first relationships between organic composition and key mechanical properties in architectures ranging from composite laminates with nano- and micro-fiber reinforcements to scroll fibers for new types of lightweight, high strength materials for multifunctional ballistic protection.