Methacrylate-Functionalized 2,5-Diphenyloxazole for Use as Fluorescent Monomers in Plastic Scintillators

Interest in plastic scintillators for the detection of special nuclear materials (SNMs) has increased in recent years due to the development of systems capable of distinguishing between neutron and γ radiation. For example, poly(vinyltoluene) (PVT)-based scintillators overdoped with the fluorescent small molecule 2,5-diphenyloxazole (PPO) distinguish the two types of radiation via pulse shape discrimination (PSD). However, PPO overdoping leads to softening of the plastic and dopant aggregation, causing major issues with detection efficiency, lifetime, and scalability. To improve the plastic scintillator properties while retaining efficient PSD performance, methacrylate-based derivatives of PPO were synthesized for copolymerization with vinyltoluene. The use of polymerizable dopants results in PSD capable plastic scintillators with increased mechanical and thermal stability while eliminating dopant aggregation and leaching.