Melamine and phytic acid (a molecule naturally found in plants) were reacted in aqueous solutions. The six phosphates in phytic acid reacted with six melamines, and two-dimensional nanoflakes were formed in drying (MEL-PA). This product was then tested at 1 – 3 % loadings in polypropylene (PP). Dispersion is shown to be good. 2% MEL-PA reduced peak heat release from 756 to 608 kW/m2 and also significantly reduced smoke release rate. The flame retardancy effect is considered to result from a physical barrier role of the D2-nanoflakes, char generation (phosphorus) and dilution of oxygen (release of water and ammonia).
“Facile preparation of layered melamine-phytate flame retardant via supramolecular self-assembly technology”, S. Shang et al., Journal of Colloid and Interface Science 2019 https://doi.org/10.1016/j.jcis.2019.06.015