ENABLING IN-SPACE MANUFACTURING OF REACTIVE THERMOSET COMPOSITE VIA FLEXIBLE CONTAINMENT

Thermoset composites offer superior durability and thermomechanical performance compared to thermoplastic counterparts, yet their application toward in-space manufacturing (ISM) is hindered by limited shelf life, resin volatility, and high processing costs. To address these challenges, this study utilizes frontally polymerizable (FP) resins—specifically catalyzed dicyclopentadiene (DCPD)—infused into carbon fibers and encapsulated within sealed, impermeable, compliant polymer films. This containment strategy significantly enhances storage stability, exceeding six months at -20°C, and effectively suppresses resin volatility in vacuum environments, limiting total mass loss to < 1% during cure. The improved storage life is attributed to the containment’s prevention of water ingress, which otherwise prevents the tributyl phosphite inhibitors’ oxidation. By leveraging the rapid, reactive nature of FP resins, the sealed prepregs were thermally cured in just 5 minutes at 155°C with low pressure (11 psi). The resulting composites achieved high-quality structural properties, including high fiber compaction shown through micrographs, high glass transition temperature (~160°C) and high flexural modulus (~180 GPa). These properties remained consistent even after the six-month storage period. Finally, we demonstrate the scalability of this method through the fabrication of tubular longerons and showcase its versatility with other reactive systems, such as radical-induced cationic FP epoxies. This work establishes a viable pathway for low-energy, rapid manufacturing of high-performance structures in extreme environments