Flexible bioinspired epoxy composites reinforced with graphene oxide and leather fiber

This study reports the development of a novel epoxy flexible sheet reinforced with graphene oxide (GO) and leather fiber (LF) to enhance mechanical strength and thermal stability while maintaining flexibility. The formulation eliminates solvents, incorporates polyphenol additives, and utilizes collagen-rich LF from waste leather, ensuring both eco-friendliness and cost-effectiveness. Physicochemical analyses confirmed hydrogen-bond-mediated interactions and uniform matrix integration. The composite exhibited a 45% increase in compressive strength (32.8 MPa against 22.5 MPa), improved elongation at break (7.6% against 4.8%), and a tougher stress–strain response than the control. Thermogravimetric analysis revealed enhanced thermal resistance with residual char yields exceeding 18% against 12% in the control. These results validate the potential of the LF–GO hybrid reinforcement for next-generation flexible composites with promising applications in wearables, structural coatings, and flexible electronics.