Tri-layer laminated composites with polyethylene and carbon fiber for hydrogen transportation

Hydrogen transportation is one of the critical links for hydrogen energy applications and has commonly achieved via cost-efficient metal pipelines, which are severely hampered by their complex manufacturing processes and susceptibility to hydrogen embrittlement in hydrogen-containing environments. Polyethylene (PE) as a promising alternative has its attributes such as light weight, good flexibility, simplified manufacturing/connection processes, and low cost, but it has inadequate mechanical properties and significant hydrogen permeation and leakage problem. To address these issues, in this study, we developed tri-layer laminated composites using high-density polyethylene (HDPE) and carbon fiber (CF) mesh. A polyethylene composite (PEC) was synthesized using nanofillers in combination with a slurry coating technique. The CFs were harnessed as a reinforcement layer in a PE matrix to enhance the composite's tensile strength and impact resistance. The PEC/CF/PEC triple-layer structure enhanced the mechanical reinforcement from the CFs, effectively retarded the gas permeation, and formed the hydrogen barrier. Results showed that the fabricated laminated composites exhibited strong interfacial bonding and uniform distribution of the fillers and CFs within the HDPE matrix, and significantly improved physical, mechanical and electrical properties. Compared to those of pure HDPE, the PEC/CF/PEC composites demonstrated significantly reduced hydrogen permeability and flame retardancy, suitable for applications such as hydrogen storage tanks, long-distance hydrogen pipelines, or firefighting equipment.