A facile and sustainable preparation of effective biomass macromolecular flame retardants for epoxy resins with improved flame retardation, smoke suppression, and mechanical performance

The preparation of biomass flame retardants with efficient flame-retardant properties is conducive to the realization of sustainable development and is of great practical significance. In this work, a green and sustainable biomass flame retardant PATAPEI was prepared by using phytic acid (PA), tannic acid (TA), and polyethyleneimine (PEI) as reactants via a one-step method to develop biomass flame retardants that can synchronize enhanced flame retardation, smoke suppression, and mechanical performance of epoxy resin (EP). The EP with only a 3% PATAPEI (EP/3PTP) has a LOI value of 28.5% with a UL-94 V-0 classification. The peak heat release rate (PHRR), total heat release (THR), and total smoke release (TSR) of EP/3PTP were decreased by 29.72%, 25.80%, and 21.16%, respectively, in comparison with the ones of pure EP. Additionally, the tensile and impact strengths of EP/3PTP are higher than the ones of pure EP. PATAPEI on heating decomposes to produce phosphorus-containing acids and biphenyltriol-containing compounds, which promote to form a good char layer with the aromatic structures during the combustion of EP/3PTP. Therefore, PATAPEI has prospects of wide application in the development of sustainable biomass flame retardant EP.