Development of metal hydroxide nanoparticles from eggshell waste and seawater and their application as flame retardants for ethylene-vinyl acetate copolymer (EVA).

Recently, calcium hydroxide and magnesium hydroxide nanoparticles have attracted a lot of research interest in different sectors: food, packaging, health, automotive construction and food application. In the present study, we report development of bio-material calcium hydroxide nanoparticles (Ceg-Ca(OH)2), obtained from chicken eggshell collected from the food industries as well as magnesium hydroxide nanoparticles obtained from seawater (Seaw-Mg(OH)2). The flame-retardant behavior of Ethylene-Vinyl Acetate copolymer (EVA) containing different blends of Ceg-Ca(OH)2 and Seaw-Mg(OH)2 nanoparticles has been evaluated using cone calorimeter. Our results showed the interest of combining both nanoparticles. In fact, the partial substitution of small Seaw-Mg(OH)2 content (10 wt%) by Ceg-Ca(OH)2 enables further reduction of pHRR from 251 to 206 kW/m2 without any reduction of the composite time to ignition (52 s). Furthermore, the partial substitution of 40 wt% Seaw-Mg(OH)2 nanoparticles by Ceg-Ca(OH)2 enables high flame retardant effect as well as the generation of cohesive residue.