Preparation of epoxy@Schiff base network composites with high fire safety, smoke suppression, and physical properties

A Schiff base network incorporating phosphorus and triazine (PN-SNW) was synthesized, and as-prepared PNSNW was mixed into epoxy resin (EP) to prepare EP@PN-SNW composites. The EP@PN-SNW composites containing 8 wt% PN-SNW showed a notable reduction of 40.2 % in peak heat release rate (PHRR), 34.2 % in total heat release (THR), 52.7 % in total smoke production (TSP), and 66.2 % in peak CO release rate (PCOP) when compared to the neat EP. Meanwhile, the Limiting Oxygen Index (LOI) value increased from 24.0 % to 32.6 %, and the composites achieved a UL-94 V-0 rating. This enhancement is attributed to the formation of a denser carbon layer in the EP@PN-SNW composites and the substantial generation of amine gases during combustion. Notably, the EP@PN-SNW composites exhibited an increase in Tg and improved mechanical properties, thereby confirming their exceptional compatibility with the EP matrix. Furthermore, the presence of PN-SNW effectively enhanced the water resistance of the EP matrix, broadening its potential applications in polymer materials.