Submicron-Sized, High Crystalline Graphene-Reinforced Meta-Aramid Fibers with Enhanced Tensile Strength

Aramid fiber is highly regarded for its outstanding properties and is widely used in various industrial applications. Among the different types of aramid fibers, meta-aramids, particularly poly(m-phenylene isophthalamide) (PMIA), are known for their exceptional flame retardance, high-temperature resistance, excellent electrical insulation, and remarkable chemical stability. As a result, PMIA-based materials find extensive use in industries focused on fire prevention, heat protection, and related applications. However, PMIA fibers have limitations due to the lack of conjugation between amide and benzene ring bonds in their molecular structure, resulting in flexible segments with low crystallinity, which in turn leads to inferior mechanical strength. Researchers have shown great interest in nanocomposites as a means to overcome these limitations. In this context, graphene nanocomposites have gained significant attention. Graphene, with its benzene ring arrangement within its layers, easily bonds with polymers possessing a similar structure. This property makes graphene a promising candidate for enhancing the mechanical strength of aromatic polymers like PMIA. Moreover, small-sized graphene particles exhibit superior dispersibility within fibrous polymer matrices, leading to more effective reinforcement compared to larger graphene sheets. Consequently, incorporating high-quality, small-sized graphene into polymer matrices can substantially improve the properties of these polymers. There is a growing demand for enhancing the mechanical characteristics of aramid fibers to expand their applications beyond traditional uses. This research demonstrates how sub-micron-sized graphene improves the structural integrity and mechanical strength of PMIA fibers. The results show a remarkable 46% enhancement in tensile strength compared to unmodified PMIA fibers. While the graphene/PMIA fiber exhibits exceptional mechanical properties, it also holds great potential for applications in wearables, flexible sensors, and various other domains, thanks to graphene's versatile characteristics. This research underscores the importance of utilizing small-sized, high-quality graphene to develop more robust carbonaceous nanocomposite fibers suitable for a wide range of commercial purposes. Beyond its immediate impact on PMIA fibers, this research represents a significant step forward in advancing the utilization and growth of graphene materials in various applications.