Hydrogen-rich composites for cosmic radiation shielding with enhanced mechanical properties and space environment applications

Abstract

In the new space era, cosmic radiation shielding is important for satellites equipped with highly integrated electronic equipment and astronauts participating in long-term space missions. Commercial off -the-shelf is being used as an electronic device for high-performance, low-cost satellites but is vulnerable to cosmic radiation. Because hydrogen-rich benzoxazine (HRB) contains a large amount of hydrogen, it can effectively shield radiation. The mass of an HRB radiation shield is lower than that of an epoxy shield, and its mechanical properties may be enhanced by the addition of amines or carbon nanotubes. However, when HRB is exposed to a space environment, high-energy atomic oxygen erodes its surface, while ultrahigh vacuum combined with high temperature causes outgassing. To improve the mechanical properties of HRB and its space environment resistance, multi-walled carbon nanotube (MWCNT)/HRB nanocomposites with grafted amine groups have been synthesized in this study. The tensile properties of these nanocomposites were evaluated, and their space environment resistance was determined using special equipment that simulates a space environment, including high-energy atomic oxygen irradiation. The obtained results revealed that the proposed NH2–MWCNT/HRB nanocomposites were superior to HRB in terms of their tensile properties, outgassing performance, and atomic oxygen resistance. Therefore, these materials can potentially replace epoxy polymers in space missions that require cosmic radiation shielding. The application of stealth design to satellites provides an advantage in reconnaissance activities by evading ground observation and increasing survivability by preventing attacks from anti-satellite weapons. A shield that absorbs microwave irradiation was developed for incorporation into an ultra-high-molecular-weight polyethylene (UHMWPE)/hydrogen-rich benzoxazine composite for cosmic radiation shielding and to prevent electronic malfunction. Through the application of a polydopamine coating to UHMWPE followed by the grafting of carbon nanotubes, microwave absorption was achieved and the mechanical properties were improved. Moreover, radiation dose analysis confirmed that the proposed material exhibited a higher radiation shielding performance than conventional radar absorbing structures. UHMWPE/hydrogen-rich benzoxazine composite (UHC) exhibits excellent cosmic radiation shielding. However, the low interfacial adhesion of UHMWPE causes low flexural strength and delamination of the UHC. We increased the interlaminar shear strength of UHC via polydopamine coating, MWCNT, and amine grafting on UHMWPE. The total mass loss and collected volatile condensable material tests were performed on the UHC to confirm for space environmental suitability. The proposed materials are expected to be utilized as a cosmic radiation shielding panel for future spacecraft.