Molecular Plastics Programming: Squaramide as a Building Block

The plastics structure-property correspondence has been conventionally identified through either a forward discovery chemistry approach or a reverse analysis physics approach. The viewing of each monomer unit as a nondivisible entity limits these approaches as an inherently nonprogrammable tool. Herein, molecular plastics programming is reported as an effective prescriptive strategy for achieving programmable molecular, macroscopic correspondence. With each monomer envisioned as a divisible entity constituted with building blocks (rigid, flexible, spacer coupling, linker), a set of guiding principles has been established for the predictive mapping of the polymer chain architecture to physical properties (thermal, mechanical, brittle, or ductile). Polymer main-chain rigid-flexible-building-block coupling is established as a feasible route toward mechanical activation and therefore ductility. Squaramide has been utilized as a building block for the design and synthesis of an amorphous-phase, ductile, and degradable plastic, showcasing molecular plastics programming as a promising platform for precision plastics engineering and sustainable polymer development.