Flame‐retardant behavior and protective layer effect of phosphazene‐triazine bi‐group flame retardant on polycarbonate

Abstract

A series of flame‐retardant polycarbonate (PC) composites with different ratios of phosphazene‐triazine bi‐group flame retardant (A3) were prepared. The flame retardant performance and thermal stability of PC/A3 composites were characterized by LOI, UL 94 vertical burning test, cone calorimetry test and TG. Results show that when the addition of A3 is 13.5%, the PC/A3 composite can pass UL94 V‐0 level with a LOI value of 29.3% and reduce the peak heat release rate by 47.5% during the combustion. TG results show that adding 5% A3 can increase the initial decomposition temperature of the PC by 7°C in nitrogen and 9°C in air. Investigation of the morphology and chemical structure of char residue demonstrates that A3 promotes the formation of more complete and compact char residue which acts as physical barriers to inhibit the transfer of heat and oxygen, resulting the good flame retardant properties. The analysis of gaseous pyrolysis product reveals that A3 also exerts a flame‐retardant effect in gas phase by releasing PO· free radicals.

Synthesis of phosphazene‐triazine bi‐base sulfonate and its applications in flame‐retardant modified polycarbonate

“…The powder sample was thoroughly mixed with potassium bromide and then pressed into a pellet. The 1 HNMR and 31 PNMR were recorded on a Bruker 600 M spectrometer CDCl 3 as the solvent and tetramethylsilane (TMS) as internal standard. The PE Avio 200 model element analyzer is used to test P and Na elements' content in the sample.…”

“…The peak at 6.77 ppm corresponding to the hydrogen near the triazine ring of hydroquinone, the peak at 7.07 ppm in the 1 H spectrum was attributed to the hydrogen near the phosphazene of hydroquinone, the peaks at 7.35 ppm is the hydrogen near the triazine ring of p-hydroxybenzene sulfonic acid and the peaks at 7.42 ppm is the hydrogen of p-hydroxybenzene sulfonic acid far away from the triazine ring. The results of 31 P NMR (Figure 3) showed that the peak at 20.61 ppm was the fully substituted phosphorus. The elemental analysis result shown in Table 2.…”

Construction of crosslinking network structures by addingZnOandADRin intumescent flame retardantPLAcomposites

“…Extensive studies have been reported on PLA flame retardants 5–7 . The metal oxides, 8,9 the phosphorus‐based systems, 10–12 and the hyper branched polymers 13,14 have been applied in the flame retardant PLA system, and the flame retardant properties and mechanism have been thoroughly researched and discussed. However, the addition of flame retardants inevitably inhibits the mechanical properties of PLA composites 15–17 .…”

Synergistic effect of polyimide charring agent and hexaphenoxycyclotriphosphazene on improving fire safety of polycarbonate: High graphitization to strengthen the char layer

“…Bisphenol A polycarbonate (PC), the fastest growing general engineering plastic, has been widely used in the construction, automotive, electronic, electrical industries, and so forth, due to its many remarkable physical and chemical properties including good thermal stability, high mechanical strength, excellent transparency, and high electric insulation 1,2 . As widely known, poor flame retardancy is a disadvantage of most polymers.…”