ABPBI/MWCNT for proton radiation shielding in low earth orbit

When planning for any space mission, shielding against ionizing radiation is essential. Polymers, combined with a nano-filler material to reinforce and enhance the polymer properties, can provide a sufficient radiation shielding function with lower weight and less secondary radiation generation than traditional shielding materials such as aluminum and high-density polyethylene. In this study, poly(2, 5)benzimidazole/multi-walled carbon nanotube (ABPBI/MWCNT) nanocomposites were fabricated and evaluated for their proton radiation shielding capabilities in the low-earth orbit region of space. The radiation shielding effectiveness of the ABPBI/MWCNT nanocomposites was experimentally evaluated by comparing their proton transmission properties and their secondary neutron generation to those of pristine ABPBI. The results showed that adding MWCNTs to the ABPBI matrix further reduced the secondary neutrons generated by the pristine ABPBI. In addition, the depth profile showed that proton penetration into the bulk of the composite decreased as the MWCNT weight percentage loading increased. The MWCNT-loaded composites showed improved resistance to proton radiation-induced damage compared to the pristine ABPBI membrane. This was evident from the visible damage observed in the scanning electron microscopy micrographs of the pre- and post-irradiated ABPBI membranes. Furthermore, composites containing MWCNTs displayed improved thermal stability over the pristine ABPBI for both pre- and post-irradiation composites. The overall characteristics presented have shown ABPBI/MWCNT nanocomposites as an effective material for application in the space industry.