Irradiation performance of polytetrafluoroethylene (Teflon®) in a mixed fast neutron and gamma radiation field

Samples of polytetrafluoroethylene have been irradiated with a mixed field of fast neutrons and gamma rays using the MIT Research Reactor. Dose levels from ∼0.3 to ∼50×106 Gy for gamma and from ∼0.13 to 80×104 Gy for fast neutrons were used. Weight loss, fluorine loss, and swelling were measured quantitatively. Subjective mechanical property tests were also performed to assess embrittlement. Aside from high levels of embrittlement, no large changes, ≳1.5%, were observed in the properties which were assayed even at the highest doses.