Research progress on rare earth radiation-resistant polymer matrix composites

High-energy photons in space environments, such as X-rays, thermal neutrons, and gamma rays, can cause ionization in polymer materials, leading to covalent bond breakage and degradation reactions. These reactions result in effects such as embrittlement, loss of elasticity, flaking, softening and stickiness, loss of mechanical strength, and gas emission, which can cause temporary damage or permanent failure of aerospace materials or devices. Rare earth elements have excellent radiation resistance to neutrons, high-energy photons and gamma rays due to their high absorption cross sections and atomic numbers. The photoelectric effect, Compton effect and electron pair effect of rare earth elements are firstly introduced in this paper. Next, the domestic and international research progress on the radiation resistance of rare earth elements in polymer materials, including fibers, plastics, rubber, epoxy resins, polyvinyl alcohol (PVA), and chitosan are reviewed. The discussion covers the incorporation of rare earth elements through doping, nanomaterial formation, and organic salts, utilizing preparation techniques such as co-precipitation synthesis, copolymerization, blending and extrusion, and molding. Testing methods include cobalt irradiation, neutron radiation, Monte Carlo simulations, and MCNP program calculations for neutron shielding. Comparative results with heavy metal lead demonstrate that rare earth elements significantly enhance the radiation resistance of polymer materials. Given their non-toxic and lightweight advantages, rare earth elements are expected to replace heavy metals like lead in applications within the medical, nuclear, and aerospace industries. The paper also provides a forward-looking perspective on the development of rare earth-based radiation-resistant polymer composite shielding materials in space environments.