Heat-Resistant Chitosan-Based Adhesive for Lunar Mare Simulant Brick-to-Fabric Adhesion

Abstract As lunar exploration advances, the development of in situ resource utilization (ISRU) has become critical for enabling sustained surface operations and reducing payload mass. Lunar regolith-based bricks are promising construction materials for applications such as launch and landing pads, roads, habitat reinforcement, and radiation shielding. However, bonding these lunar bricks to a flexible fabric such as carbon fiber remains a significant challenge due to their very different surface chemistries and mechanical properties. In this study, a fire-resistant adhesive composed of chitosan, acetic acid, and pentaerythritol was developed to bond lunar mare simulant (LMS) bricks to woven carbon fiber fabric. The thermal stability of the adhesive was characterized using thermogravimetric analysis (TGA), while adhesion was evaluated through lap shear and oxygen-methylacetylene-propadiene propane (oxy-MAPP) torch testing. The adhesive maintained structural adhesion under direct flame exposure with no bond delamination, brick displacement, or detachment for any adhesive tested. Despite the front side of the samples reaching extreme temperatures >2200 °C, the bonded brick-to-fabric samples remained intact through both continuous and cyclic flame exposures. These results demonstrate that this simple biobased adhesive provides durable, heat-resistant bonding for lunar brick-to-fabric assemblies.