Achieving Outstanding Mechanical Performance in Reinforced Elastomeric Composite Fibers Using Large Sheets of Graphene Oxide

A simple fiber spinning method used to fabricate elastomeric composite fibers with outstanding mechanical performance is demonstrated. By taking advantage of the large size of as‐prepared graphene oxide sheets (in the order of tens of micrometers) and their liquid crystalline behavior, elastomeric composite fibers with outstanding low strain properties have been fabricated without compromising their high strain properties. For example, the modulus and yield stress of the parent elastomer improved by 80‐ and 40‐fold, respectively, while maintaining the high extensibility of ∼400% strain inherent to the parent elastomer. This outstanding mechanical performance was shown to be dependent upon the GO sheet size. Insights into how both the GO sheet size dimension and dispersion parameters influence the mechanical behavior at various applied strains are discussed. A straightforward approach to prepare liquid crystalline dispersions of poly­urethane/graphene oxide (PU/GO) formulations has enabled the fabrication of high performance elastomeric composite fibers. The PU/GO fibers containing large GO sheets display remarkable reinforcement in modulus and yield stress (low strain properties) without compromising the extensibility and stretchability (high strain properties) inherent to PU. These fibers are produced using a very simple, continuous, and highly scalable fiber wet‐spinning process.