Eco-friendly one-pot supramolecular-assembly of P-N flame retardant for fire-safe epoxy resin.

Flame retardant treatment of epoxy resins to reduce their flammability for extending their range of applications attracts considerable attention. However, the synthesis process of conventional flame retardants is complicated and involves organic hazardous solvents. Meanwhile, how to ensure both the flame-retardant and mechanical properties is a long-standing and actual difficult problem. In this work, a supramolecular flame retardant (ATPFR) is facilely created by one-pot reaction, using cheap and accessible raw materials in an ecologically benign aqueous solvent. ATPFR is applied to improve the fire safety of epoxy (EP) thermosets. With only 5wt% ATPFR addition, the limiting oxygen index of EP thermoset can reach 28.5%, and can reach UL-94 V-0 rating with a significant "blow-out effect". The cone calorimetry test reveals that the EP thermoset with 5wt% ATPFR has a 75.8% reduction in the peak heat release rate (p-HRR) and a 67.3% reduction in the peak smoke production rate (p-SPR), respectively, compared with the pure EP. Additionally, EP composites with the small amount of ATPFR exhibited a slight decrease and maintain good mechanical properties. Therefore, the facile synthesis and application of this supramolecular flame retardant provide a reliable way for the construction of polymer materials with environment-friendly and effective flame-retardant system. This article is protected by copyright. All rights reserved.