Fecha de publicación: -- Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE To overcome the deficiency of poor high-temperature thermal stability of the char layer of epoxy resin in traditional flame retardant systems, the structural units of piperazine and phenylboronic acid are introduced to reinforce the char layer and optimize its quality. Furthermore, the multiple active sites in the flame retardant molecule, including secondary amine groups and boronic acid hydroxyl groups, can enhance the compatibility with the epoxy resin matrix and interfacial bonding strength, thus improving the mechanical properties of the material.

ABSTRACT
To overcome the flammability, poor charring, and brittleness of epoxy resin (EP), a flame-retardant additive, BPD, was synthesized from N-aminoethylpiperazine, 4-acetylphenylboronic acid, and DOPO, and then incorporated into EP to obtain EP/BPD composites. With 3 wt% BPD, the LOI increased from 25.7% to 28.3%, and the UL-94 rating improved from NR to V-0. At 5 wt% BPD loading, pHRR, THR, SPR, TSR, COP, and CO2P decreased by 39.1%, 10.2%, 42.8%, 74.3%, 30.0%, and 39.3%, respectively, versus pure EP, demonstrating excellent flame retardancy, smoke suppression, and fire safety. Moreover, 1 wt% BPD raised impact strength to 28.79 kJ/m2 (65.9% increase), while tensile (51.98 MPa) and flexural strengths (69.78 MPa) remained nearly unchanged, achieving a synergistic balance of flame retardancy and mechanical toughness.