Self-healable acrylic/polyolefin-reinforced composites for H2 fuel applications

Abstract

Fiber-reinforced composites, despite their high strength-to-weight ratios, are still susceptible to damage. Integrating self-healing matrices into these multi-phase materials offers a promising approach to extend their service life and functionality while preserving mechanical performance across multiple damage-repair cycles. In this study, we developed cost-effective composites using a van der Waals (vdW) driven self-healing thermoplastic poly(methyl methacrylate/n-butyl acrylate) [p(MMA/nBA)] matrix reinforced with high-strength polypropylene (PP) fibers. These materials can be utilized as the self-healing inner layers in engineered multilayered H₂ fuel dispensing hoses. These studies show that a p(MMA/nBA) copolymer matrix with a 50/50 monomer molar ratio reinforced with PP fibers wound at a 45° angle with respect to the object's longitudinal axes maintains its mechanical integrity after 25 000 damage-repair cycles. Combining experimental data with finite element analysis (FEA), these studies show that these materials exhibit favorable stress distributions under bending loads over multiple cycles. The maximum stresses occur near the fixed end in the outermost layer, while the innermost layer experiences the lowest stresses. The self-healing is effective over a wide temperature range from −196 °C to +85 °C, making them suitable components for demanding, complex energy applications in H₂ fuel storage and larger delivery systems.