Synthesis, thermal degradation, and flame retardance of novel triazine ring-containing macromolecules for intumescent flame retardant polypropylene

Two novel triazine ring-containing macromolecules, designated as charring-foaming agent 1 (CFA1) and charring-foaming agent 2 (CFA2), were synthesized by a series of polycondensation reactions. Their chemical structures were analyzed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (¹³C solid-state NMR), and elemental analysis, and their thermal degradation properties were assessed by thermogravimetric analysis (TGA). TGA data revealed that CFA1 and CFA2 show high thermal stability and have a high propensity for char formation, their initial decomposition temperatures being 300.2°C and 287.1°C, and their char residues at 800°C amounting to 32.2 wt % and 21.1 wt %, respectively. CFA1 presents higher thermal stability and more char residue than CFA2. Based on experimental results of the flame retardancy (limiting oxygen indices values and UL-94 V-0 rating) and the TG data of new intumescent flame retardant polypropylene (IFR-PP) containing CFA1 and CFA2, CFA1 exhibits more outstanding intumescent flame retardance than CFA2. IFRs containing CFA1 and CFA2 enhanced Notched Izod Impact strength of IFR-PP, and slightly lower tensile strength of IFR-PP. IFR2 shows more advantageous effect on mechanical properties of IFR-PP than IFR1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010