Thermal Degradation Kinetics of Alginate Fiber Containing a Novel Graphene-Based Flame Retardant

The improvement of flame retardants in controlling polymer combustion behavior is mainly based on their effect on the polymer thermal degradation behavior. In this article, the Kissinger method and Flynn-Wall-Ozawa method were used to study the thermal degradation behavior of alginate (Alg)/graphene composite fibers. The results of activation energy calculated by the two methods were very consistent. The addition of a graphene-based flame retardant (GO-DOPO-V, where GO represents graphene oxide, DOPO represents 9,10-dihydro-9-oxy-10-phosphoxanthine-10-oxide and V represents vinyltrimethoxysilane) increased the thermal degradation activation energy of the Alg composite fiber and enhanced the thermal stability and flame retardancy of the fiber. The Flynn-Wall-Ozawa method further revealed that the addition of GO-DOPO-V induced a condensation reaction of the polymer at the early degradation stage of the Alg composite fibers, leading to a decrease in the thermal degradation activation energy. At the final stage of the thermal degradation, with the formation of a char layer, the thermal degradation and activation energy of the Alg composite fibers were improved under the action of GO-DOPO-V, and the flame retardancy of the Alg composite fibers was enhanced.