A phosphorus/silicon-containing compound for enabling transparent epoxy resin synchronously with excellent fire safety and room temperature phosphorescence

Enabling transparent epoxy resin (EP) synchronously with excellent fire safety and room temperature phosphorescence is rarely reported. In the present work, a phosphorus/silicon-containing compound (marked as BTPC) was synthesized via nucleophilic substitution reaction and doped into EP. The incorporation of 2.8 wt% BTPC endowed EP/BTPC (EP-2.8) with comparable transparency and excellent fire safety, including UL-94 V-0 rating and a limiting oxygen index of 33 %, with 46 % and 33 % reduction of peak heat release rate and total heat release as compared to neat EP. BTPC exerted flame retardant effect in gas phase by diluting combustibles and quenching of reactive free radicals, and in condensed phase through formation of dense char layer to isolate the transfer of heat and combustibles. Furthermore, both EP and EP/BTPC blends exhibited room temperature phosphorescence, the phosphorescence lifetime and photoluminescence quantum yield of EP-2.8 were detected to be 638 ms and 8.14 %, respectively. Remarkably, EP-2.8 remained afterglow phenomenon after treatment at high temperature (423 K) for 20 min or in aqueous and strong acid (or base) for one week. Furthermore, EP-2.8 exhibited exceptional afterglow stability and environmental durability. This work provides a strategy for expanding the potential application of transparent EP with room temperature phosphorescence in some harsh environments. • It is the first time to report that neat EP emitted room temperature phosphorescence under high-power UV excitation. • The introduction of BTPC not only endowed transparent EP with excellent fire safety but prolonged afterglow duration of EP. • EP/2.8 wt% BTPC blend remained afterglow phenomenon after suffering from harsh treatments.