Polymer and polymer-based composites for space radiation mitigation in food systems: Materials, mechanisms, and future perspectives

Long-duration space missions to the Moon, Mars, and deep-space environments require advanced food systems capable of maintaining nutritional quality, safety, and stability under prolonged exposure to ionizing radiation. Space radiation, primarily originating from galactic cosmic rays (GCR), solar particle events (SPE), and secondary radiation produced by particle–matter interactions, can significantly degrade both food components and packaging materials. Radiation-induced effects such as lipid oxidation, protein denaturation, vitamin degradation, polymer chain scission, crosslinking, and increased permeability compromise food quality, shelf life, and packaging integrity during extended missions. Consequently, the development of lightweight, multifunctional, and radiation-resistant packaging materials has emerged as a critical challenge in space food systems. This review comprehensively examines the role of polymers and polymer-based composites in mitigating radiation-induced degradation in space food applications. The review discusses the characteristics of the space radiation environment, radiation–matter interaction mechanisms, and the influence of radiation on food macromolecules and packaging systems. Conventional polymers including polyethylene (PE), polypropylene (PP), ethylene vinyl acetate (EVA), polyimides, polycarbonate (PC), polydimethylsiloxane (PDMS), and polyether ether ketone (PEEK) are critically evaluated for their shielding performance, radiation stability, and suitability for food packaging applications. Particular emphasis is placed on hydrogen-rich polymers for neutron moderation and on the incorporation of high-atomic-number (high-Z) fillers, boron-containing compounds, nanomaterials, and multifunctional additives to improve attenuation efficiency against gamma rays, neutrons, and secondary radiation. The review further highlights recent advances in polymer composites, nanocomposites, multilayer packaging systems, active and intelligent packaging technologies, and sustainable biopolymer-based materials for next-generation space food packaging. Key challenges include radiation-induced material deterioration, secondary radiation generation, nanoparticle aggregation, interfacial incompatibility between fillers and polymer matrices, limited recyclability, and the need to ensure long-term environmental stability during extended exposure to space radiation. Overall, this review provides a multidisciplinary perspective on advanced polymeric materials for radiation mitigation and identifies future research directions for developing safe, lightweight, and sustainable food packaging systems that support deep-space exploration missions.