Flame-retardant treatment of polyester fabric by graphene sodium alginate/graphene microcapsules

Graphene(Gh) microcapsules with particle size ranging 750~1450 nm were prepared by coating ammonium polyphosphate(APP) with graphene, and then blended with sodium alginate hydrogel to produce flame-retardant coating solution. Sodium alginate/graphene microcapsules/polyester fabric (SA/APP@Gh/polyester fabric) was further synthesized with dipping rolling method, followed by analysis on its flame retardancy, mechanical properties and thermal properties. The results showed that the ultimate oxygen index of the polyester fabric, treated with the flame-retardant coating solution containing 25 g/L sodium alginate and 8 g/L graphene microcapsules, increased from 19.80% (original polyester fabric) to 27.88%, met the standard of flame resistant fabric. The vertical combustion test index of SA/APP@Gh/polyester reached B-2，with the melting droplet phenomenon disappeared after combustion. The char of SA/APP@Gh/polyester fabric became continuous and dense, while the mechanical properties reduced with breaking strength decreased from 138.48 N to 108.86 N. The temperature at which SA/APP@Gh/polyester fabric reached the maximum thermal decomposition rate did not show significant change. The carbon residue rate of SA/APP@Gh/polyester fabric increased from 12.07% to 26.98%, and the maximum mass loss rate decreased from 1.79%/℃ to 0.96%/℃. The thermal enthalpy increased from 50.43 J/g to 68.40 J/g, and the thermal conductivity increased from 5.26×10–5 W/(cm·℃) (original polyester fabric) to 8.42×10–5 W/(cm·℃), indicating improved thermal properties. © 2023 Fine Chemicals. All rights reserved.