Synthesis of Flame Retardant with Synergistic Effect of Nitrogen, Sulfur, and Silicon and Its Application in Polycarbonate

Based on the synergistic effect of nitrogen, sulfur, and silicon on flame retardancy, a flame retardant containing nitrogen, sulfur, and silicon of 2, 2'- (1, 1, 3, 3-tetramethyldisiloxane-1, 3-diyl)bis(propane-3, 1-diyl)-bis(potassium-4-aminoethanesulfonate-6-(4-(hydroxyphenyl)amino)-1, 3, 5-triazine)(KTS) was synthesized via the nucleophilic substitution reaction of cyanuric chloride, aminoethanesulfonic acid, p-aminophenol, 1, 3-bis (3-aminopropyl) -1, 1, 3, 3, -tetramethyldisiloxane. The PC/KTS composites were prepared by melt blending. The thermal stability and flame retardancy of the composites were investigated by thermogravimetric analysis(TGA), limiting oxygen index(LOI), vertical combustion(UL 94) and cone calorimetry(CONE). The TGA results show that the incorporation of KTS promotes the decomposition and charring of the materials at a relative low temperature, and the further decomposition of the materials is restrained. Unfortunately, the thermal stability of the composites is decreased. In addition, when mixing with 0.5% KTS with PC, the flame retardancy of the materials is effectively changed, the LOI arrives at 34.60% and passes the UL 94 V-0 rating, and then the pk-HRR and pk-SPR of composites are reduced by 41.25% and 35.3%, respectively, compared with pure PC. The SEM and Raman spectra results indicate the introduction of KTS is more conducive to the formation of high surface regularity and high graphitization degree char layer on the surface of the inner materials, played a functional role in condensed phase flame retardancy. © 2021, Editorial Board of Polymer Materials Science & Engineering. All right reserved.