Preparation and characterization of a novel oligomeric charring agent and its application in halogen-free flame retardant polypropylene

Flame retardant properties and mechanism of an efficient intumescent flame retardant PLA composites

“…For the PLA/IFR composite, an intumescent char layer was observed with some small cracks, and there were some folds on the surface, which could act as a skeleton to strengthen the surface layer. [15,16] These results provided positive proof that the synergistic effect between APP and CNCA-DA could accelerate to form an intumescent char layer with excellent quality, and it could prevent heat and flammable gas from transferring between the flame zone and the burning substrate. The char layer could protect the underlying materials from further burning, and retard the thermal degradation of the PLA/IFR, thereby leading to better flame retardant properties.…”

“…It can be found that the major thermal degradation step of IFR happened at 375°C, which could be attributed to the release of water and ammonia; and the second one could be assigned to the decomposition of char residue, which took place at 583°C. [16] In Figure 4, Curve IFR was the experimental result, and curve IFR-calculation is the result calculated from the experimental results of APP and CNCA-DA on the base of their percentage in the IFR system according to formula 1. As could be seen from Fig.…”

Influence of zinc borate on the flame retardancy and thermal stability of intumescent flame retardant polypropylene composites

“…The parameters include the heat release rate (HRR), the total heat release (THR), smoke produce rate (SPR), total smoke produce (TSP) and mass loss rate (MLR) [26][27][28][29][30]. are similar to the HRR and THR curves.…”

“…The char still contained P and O elements, but the contents were much lower than those before soaked in water, indicating that most of P and O were in polyphosphate or other complex containing P and O [32][33]. Compared with PP/IFR, the char of PP/IFR/1%ZB after soaked in water contains more P (2.28 %) and O (12.19 %), inferring that ZB could promote more P and O entering onto the polyaromatic ring to form more interconnected network and enhance the strength of the char layer [29][30][31]35]. …”

“…In our previous work, CNCA-DA has been combined together with APP to form a novel IFR system, which has been proved to have good flame retardancy for PP [28]. Moreover, lanthanum oxide (La 2 O 3 ) and 4A zeotile showed obvious synergistic effects on the flame retardancy of the PP/IFR systems [29][30]. In this work, ZB was selected to investigate the synergistic effect and mechanism with PP/IFR composite.…”