Synthesis and flame inhibition efficiency of a novel Fe-based metal complex with phosphorus-containing structure

Owing to the increased depletion risk and cost of phosphate mines, the demand for low phosphorus or ecological phosphorus flame inhibitor is increasing. This study reports an experimental exploration of the combustion inhibition efficiency of bio-based transition metal complex materials containing iron and phosphorus, namely, iron @ phosphorus complex (Fe-PMC). The aim is to develop a new type of flame inhibitor with an iron-phosphorus interaction effect to replace pure phosphorus extinguishing agents. The synthesis of Fe-PMC was characterized by Fourier-transform infrared spectroscopy, X-Ray diffraction, X-ray photoelectron spectroscopy and Scanning electron microscope. The Fe-PMC (ⅰ) is the mesh porous structure connected by the accumulation of small particles, (ⅱ) is an amorphous structure with many binding sites exposed and excellent interface compatibility, (ⅲ) contains no chloride ions. Suppression tests and thermogravimetric measurements indicate that (ⅰ) Fe-PMC has a higher combustion inhibition ability than MIL-53 containing only iron, especially at low concentrations, (ⅱ) Fe-PMC reduces the laminar flame velocity of cellulose, (ⅲ) Fe-PMC greatly reduces flame temperature. The activation energy (E), pre-exponential factor (A) and char yield (Y) of cellulose pyrolysis were determined by kinetic analysis. It concluded that MIL-53 and Fe-PMC produce combustion inhibition mainly in the solid phase. These findings will contribute to the development of a flame inhibitor with low or no phosphorus and better performance. Mil-53 (iron) and Fe-PMC (iron, phosphorus) were synthesized by solvothermal process, and they were uniformly adsorbed on rectangular cellulose beds. The flame suppression efficiency of cellulose beds loaded with different amounts of Mil-53 and Fe-PMC was evaluated by down fire spreading rate and flame morphology. • Design and synthesis of bio-based transition Metal complex materials. • Synergistic inhibitory effect of iron and phosphorus elements on flame. • Innovatively designed combustion suppression experimental device and quantitative suppression mechanism analysis.