Basalt Fiber-Reinforced Sulfur Polymer Matrix Composites

To facilitate the goals of a sustained lunar presence, there will be a need for the efficient utilization of indigenous resources. The ability to make composite articles would be hugely advantageous for the fabrication of structures having high tensile and flexural strength. Articles with such properties are required for applications such as beams for cranes. The lunar environment lacks the hydrocarbons necessary to formulate organic polymeric matrices. However, sulfur is the eleventh most abundant among the elements in average lunar mare rocks. In 2016, a process called inverse vulcanization was developed that results in chemically stable and processable sulfur-based polymers. The process is straightforward and yields a dynamic covalently crosslinked thermoset. Though, it requires a small amount of an organic molecule having multiple points of unsaturation, of which there is not an abundance on the Moon. Urobilin, formed from the natural break down of red blood cells and found in healthy urine and feces, may fit the requirements for the necessary unsaturated organic molecule. Extraction from astronaut waste could be implemented in the Universal Waste Management System (UWMS) for collection. Given the processing characteristics of sulfur polymers it may be possible to utilize basalt fiber and sulfur polymers to produce polymer matrix composites using automated composite processing techniques such as pultrusionmdash;a technique that allows structural composite materials to be made affordably by implementing automated processing. Utilizing novel polymer systems and reinforcements derived from lunar resources combined with proven automatable composite processing techniques should result in materials having enhanced tensile and flexural strength relative to wholly mineral based materials.