Chemical and thermal stability of thermoplastics in fast and mixed irradiation extremes

This study examines the stability of thermoplastics when submitted to high neutron and electron beam fluxes. Two thermoplastics were investigated, ultra-high molecular weight polyethylene (UHMWPE) containing up to 40 wt % isotopically enriched boron-10, and 3D printed acrylonitrile butadiene styrene (ABS) containing 60 wt % tungsten. FT-IR of exposed borated-UHMWPE showed small changes to its chemical structure due to oxidative degradation. Whereas thermal gravimetric analysis (TGA) indicated that about 15 wt% of tungsten was removed from the surface of 3D printed W-ABS that was directly facing the electron beam. This effect is due to the rapid energy deposition on the metal causing ablation. This study demonstrates that these two thermoplastics are not only useful in multiple industrial applications, but are also fairly resilient to extreme radiation environments. • Stability of thermoplastics in extreme environments. • Radiation exposures were provided by pool-type nuclear reactor. • Radiation exposures were provided by electron beam. • Changes in chemistry and thermal properties were analyzed. • UHMWPE and W-ABS showed good resistance to harsh radiation environments.