Improved Flexural Properties of Carbon Fiber‐Reinforced Polyamide Composites for Type IV and V Hydrogen Storage Vessels Utilizing Graphene Nanoplatelets

ABSTRACT This study explores the enhancement of bending properties in carbon fiber‐reinforced polyamide6 (PA6) composites for Type IV and V hydrogen storage vessels through the incorporation of graphene nanoplatelets (GNPs). PA6 materials, widely utilized as liner materials in such applications, require superior flexural properties and impact resistance to withstand the demands of pressure vessels. By integrating GNPs, it is aimed to improve these mechanical properties without compromising the resin's hydrogen barrier capabilities and moldability. The results revealed that the flexural strength and modulus of PA6‐based composites were significantly improved by the addition of GNPs, with 0.6 wt% identified as the optimal loading. At this composition, a well‐dispersed GNPs network acted as an effective nucleating agent, enhancing crystallinity, stress transfer, and interfacial adhesion, thereby achieving the best overall mechanical performance. In contrast, lower or higher GNPs loadings led to inferior reinforcement due to insufficient network formation or agglomeration. These improvements directly support the adaptability of the composites to hydrogen storage vessels, as superior flexural properties are crucial for withstanding high‐pressure operating conditions. Through comprehensive evaluation of the resin's properties, the optimal composition was determined, and subsequent fabrication and testing of the composites confirmed their suitability for Type IV and potential application in Type V hydrogen storage vessels.