Learning from Proteins: Circular Polymer Design from Gluten Leather to Silk-Inspired Marine-Degradable Poly(Ester Amide)s

Proteins offer a powerful blueprint for sustainable structural materials because they combine strength, toughness, flexibility, sensory function, and biodegradability through amide-rich backbones, hydrogen bonding, dynamic secondary structures, and hierarchical organization. In this talk, I will present two complementary strategies for translating protein chemistry into circular polymer materials: direct programming of native proteins and synthetic design of protein-inspired plastics.

First, we developed a protein-based vegan leather from once-discarded wheat gluten. Gluten, composed mainly of glutenin and gliadin, has intrinsic viscoelasticity arising from disulfide-bonded protein networks. Through a chemical toughener-free process involving hot pressing, thermal conditioning, and UV exposure, gluten was physically programmed into a durable leather-like material. Heat treatment promotes molecular rearrangement and hydrogen bonding, while UV-assisted oxidation induces additional covalent crosslinks through cysteine- and tyrosine-related pathways. The resulting material exhibits leather-like pliability, frictional feel, surface texture, water resistance, and high toughness, demonstrating that underutilized plant proteins can be transformed into biodegradable structural materials.

Second, we extended this protein-derived design principle to synthetic polymers by developing marine-degradable poly(ester amide)s. Conventional biodegradable polyesters often suffer from a tradeoff between degradability and mechanical strength, whereas natural proteins such as silk achieve high performance through amide-rich architectures. By incorporating amide motifs into biodegradable polyester backbones, we created poly(ester amide)s that combine processability, strong mechanical properties, fiber-forming ability, and marine biodegradability. These materials were synthesized from upcycled monomers in a scalable reactor and processed into films and melt-spun yarns.