Rheological Properties of Functionalized Smart Resins for Transport Applications †

Hydrogen is a promising alternative to fossil fuels, but its efficient storage presents significant challenges. Polymer composite vessels, especially those made from carbon fiber-reinforced plastic (CFRP), are gaining attention, due to their high strength-to-weight ratio for storing compressed or cryogenic hydrogen. The latest Type V tanks, which lack internal liners, rely solely on fiber composites for both structural integrity and gas containment, enhancing the storage volume-to-weight ratio and supporting recycling. However, this linerless design faces the challenge of preventing gas permeation. Epoxy resins, widely used in aerospace carbon fiber-reinforced composites (CFRCs), offer excellent processability and load-bearing capabilities. The addition of high-aspect-ratio nanofillers can enhance the gas barrier properties, which are essential for preventing hydrogen leakage, while also improving the mechanical, electrical, and thermal properties of the nanocomposites. This study focuses on epoxy-based composites with expanded graphite, aiming to optimize their physical properties and processing for Type V tanks, using a rheological framework to evaluate their processability and multifunctionality in transport applications.