Facile construction of organic–inorganic hybrid flame-retardant system based on fully biomass: Improving the fire safety and mechanical property of epoxy resin

[Display omitted] •A fully bio-based flame retardant was facile synthesized via mechanochemical strategies.•EP composites with TOSP@PAA exhibited high flame retardancy and good mechanical properties.•TOSP@PAA promoted formation of char layer and released non-flammable gases in EP during heating.•TOSP@PAA also revealed excellent flame retardancy for fibric and flexible pu foam. As the contradiction intensifies both the increasing consumption of petroleum resources and environmental protection, the exploitation and utilization of biological resources have reached an unprecedented height. Hence, an organic–inorganic hybrid system, called ammonia phytate modified oyster waste nanosheets (TOSP@PAA), was constructed via mechanochemical strategies and used for flame-retardant EP. The characterization revealed that TOSP@PAA showed a specific layer crosslinking structure by the NH3+OP bond. The calcination experiment revealed that TOSP@PAA possessed excellent self-charring performance and formed a highly intumescent char residue layer at high temperatures. In addition, the combustion tests indicated that EP with TOSP@PAA showed noticeable fire safety (e.g., ∼74.0 % and 60.2 % decline in peak heat release rate (pHRR) and total heat release rate (THR) at only 8 wt% content) and excellent heat insulation properties. Remarkably, EP with TOSP@PAA exhibited good mechanical properties with remarkable improvement in flexural properties. The work provides new sights on the facile preparation of environmentally friendly flame retardants and explores a new way to strengthen the fire safety and mechanical property of EP.