Lignin and nanoclay based flame retardant: Kinetics study of thermal decomposition of unsaturated polyester.

The innovation of natural-based flame retardant products is an interesting field to study regarding the substitution of conventional flame retardants. In this study, lignin and clay were used as flame retardant materials to mix with unsaturated polyester (UP). Flame retardant material derived from lignin and nanoclay was prepared by mixing 12.5 percent lignin and nanoclay into UP and adding 1 percent catalyst, each mixture was stirred for 10 minutes with a stirring speed of 100 rpm to form UP-Lignin and UP-Clay, respectively. The thermal decomposition of the UP, UP-Lignin, and UP-Clay was investigated by thermogravimetric analysis (TGA) under non-isothermal conditions. Further, kinetic parameters were calculated by the Model-Based Method (Coats-Redfern) in terms of TGA results. Based on the analysis of the decomposition reaction for UP, UP-Lignin, and UP-Clay, it was found that the decomposition reaction was appropriate for first-order reactions. The addition of lignin and nanoclay to UP showed a decrease in activation energy of 67.56, 60.83, and 59.74 kJ/mol, respectively. This indicates that the presence of lignin and nanoclay in UP reduces the sensitivity of UP to temperature. [ABSTRACT FROM AUTHOR]