Sealed flexible containment strategy for long-term storage and low-outgassing to fuel in-space manufacturing of frontally polymerizable composite

Despite having better processibility, durability, and thermomechanical performances, thermoset composites raise concerns of limited storage life, resin volatility, and property consistency when considered for in-space manufacturing. The large costs in time, energy, and equipment for processing are also important selection criteria. Here, we tackle such concerns by infusing carbon fibers with frontally polymerizable (FP) resin such as catalyzed dicyclopentadiene (DCPD) and enclose them between sealed, impermeable, and compliant polymer films to demonstrate significant improvement in storage life at −20 °C (>6 months) and in containment of resin volatility during cure (<1% in total mass loss) under vacuum environments. Due to the reactive nature of FP resins, we rapidly cure the sealed prepregs thermally (5 min at 155 °C) using low energy (~1.79 MJ/kg) and pressure (11 psi) to manufacture low void composites (<1% voids) with consistent $${T}_{g}$$ (160 °C) and flexural properties (~180 GPa) after prolonged prepreg storage. The improved stability is attributed to the prevention of water ingress, which improves the effectiveness of the tributyl phosphite inhibitor. We further demonstrate scalability from flat laminates to tubular longerons along with the applicability of such containment strategy to other forms of reactive thermoset resins, including radical-induced cationic frontally polymerizable epoxies.