Abstract

Sustainable lunar and Martian missions require materials that can be manufactured, reused, and reinforced directly on planetary surfaces. This thesis develops a comprehensive framework for additive manufacturing (AM) of recycled PEKK and PEKK–regolith composites, unifying crystallization control, recycling science, and extraterrestrial filler incorporation for in-situ resource utilization (ISRU).
First, the thermal and mechanical behavior of PEKK during AM was optimized through a combined “on-the-fly” annealing strategy and a DSC–FEA post-processing method, enabling predictable crystallization, reduced warpage, and significantly improved strength and thermal stability. These principles were extended to architected geometries, showing how raster orientation, lattice topology, and heat treatment govern anisotropy and failure modes in printed structures.
PEKK was then compounded with Martian (10–30 wt%) and lunar regolith simulants (10–60 wt%), in two parallel projects. In lunar project we aimed to maximize the regolith incorporation while in Martian project we focused on maximizing the incorporation from relatively large particles (100 microns) to perforated tube silica particles (less than 20 microns) to study effect of particle morphology beside the maximum incorporation. Mechanical testing across orientations showed that moderate regolith contents maintain printability and flexural performance, while high loadings yield stiff, brittle composites suitable for compressive or sacrificial applications. A predictive tensile model incorporating porosity, filler fraction, and fracture regime was developed and validated.
To enable closed-loop ISRU, PEKK was repeatedly recycled through shredding, pulverization, extrusion, and reprinting. Across multiple cycles, PEKK preserved its chemical, thermal, and mechanical integrity, and annealed recycled material often outperformed virgin PEKK due to reduced porosity. Finally, recycled PEKK was combined with 30 wt% lunar regolith to create a circular ISRU composite filament used to fabricate functional demonstrators, including gyroid lattices and a ratchet wrench.
Collectively, this work establishes that recycled PEKK and PEKK–regolith composites are viable, high-performance, and circular feedstocks for future extraterrestrial manufacturing, providing a scalable pathway toward sustainable polymer-based ISRU on the Moon and Mars.