Reactive nano-epoxy matrix and the UHMWPE fiber composites for cosmic radiation shielding

Cosmic radiation shielding properties are important for spacecraft. Hydrogenous materials such as polyethylene have been shown effective against galactic cosmic rays (GCR) and solar energetic particles. Ultrahigh molecular weight polyethylene (UHMWPE) fibers have advanced mechanical and physical properties, which are very valuable for NASA missions. Unfortunately, poor interface in the UHMWPE fiber/polymer matrix hinders the structural integrity of the composites, and restricts the effectiveness of radiation shielding for practical applications. Fiber treatment methods can not only incur an extra cost for manufacturing the composite structures, but also may sacrifice intrinsic properties of the fibers. In our study, we fabricated a reactive nano-epoxy matrix with reactive graphitic nanofibers, which showed enhanced mechanical (including strength, modulus and toughness) and thermal properties (higher T_g, stable CTE, and higher ageing resistant), as well as wetting and adhesion ability to UHMWPE fibers. 1 GeV/nucleon ³⁵Cl ions, high energy ions for the complex GCR heavy ion radiation field, was used for the radiation tests. The results showed that the radiation shielding property was not reduced by the addition of graphitic nanofibers. The studies indicated that the UHMWPE fiber/nano-epoxy will have potential in manufacturing more durable space composites and structures.