Phosphoric acid-based hydrogen-bonded organic framework offer both photoluminescence-functionalized and excellent flame retardancy for epoxy composite

In this study, a photoluminescence (PL)-functionalized epoxy resin (EP) composite EP/PHOF-1A has been developed based on phosphoric acid-based hydrogen-bonded organic frameworks (HOFs). EP/PHOF-1A not only inherits the PL property of PHOF-1A, but also exhibits wavelength-dependence on the excitation wavelength, shows different PL responses at different excitation wavelengths of UV lamps, demonstrating potential applications in various fields. Meanwhile, EP/PHOF-1A also shows excellent flame retardancy, which greatly inhibits the release of heat, smoke and harmful gases from EP composites during the combustion process. In comparison with pure EP, the peak heat release rate (pHRR), total heat release (THR) and peak smoke production rate (pSPR) of EP/PHOF-1A were reduced by 55.8%, 30.0% and 37.9%, respectively. It's worth noting that compared with other porous material FRs, PHOF-1A can effectively reduce pHRR and THR during combustion. This study provides a rational approach for the functionalization of EP and improves the flame retardancy of EP composites to broaden their applications, which is expected to promote the development and application of functionalized polymers composites in the future.