A novel hyperbranched polyphosphamide with abundant terminal groups of silane (HBPPA-Si) was synthesized from phosphorus oxychloride (POCl₃), 4, 4′-diaminodiphenylmethane (DDM) and (3-aminopropyl) triethoxysilane (APTES), which had high thermal stability with a residual weight of 44.0 wt% at 800°C in nitrogen atmosphere. By incorporating 25 wt% of APP and HBPPA-Si with an optimum mass ratio of 1:1 into polypropylene (PP) composites, the PP/APP/HBPPA-Si composite reached V-0 rating at the UL-94 test and also obtained a maximum LOI value of 27.5%. Meanwhile, their peak heat release rates (PHRR), total heat release (THR), and total smoke production (TSP) reduced dramatically by 72.5%, 35.8%, and 62.7% respectively, when compared with virgin PP. The improved flame retardancy and smoke suppression of PP/APP/HBPPA-Si composite were ascribed to their excellent synergistic effect working efficiently in both condensed-phase and gas-phase actions. It is noticeable that the high-quality and high-quantity char residue possessing thermal-stable P- and Si-containing cross-linked structures can shield the underlying polymeric materials from further hydrolysis and simultaneously insulate the volatile fuel and heat transfer. Moreover, the weak polar silane shell of HBPPA-Si improved the interfacial compatibility of APP within the PP matrix, leading to enhanced mechanical properties with increasing HBPPA-Si concentration.

由三氯氧化磷（POCl ₃）合成了一种新型的具有丰富的硅烷端基的超支化聚磷酰胺（HBPPA-Si）），4，4'-二氨基二苯甲烷（DDM）和（3-氨基丙基）三乙氧基硅烷（APTES），它们具有很高的热稳定性，在氮气氛下于800°C时的残留重量为44.0 wt％。通过将25 wt％的APP和HBPPA-Si以1：1的最佳质量比掺入聚丙烯（PP）复合材料中，PP / APP / HBPPA-Si复合材料在UL-94测试中达到V-0等级，并且也获得了最大LOI值为27.5％。同时，与纯聚丙烯相比，它们的峰值放热率（PHRR），总放热（THR）和总烟雾产生（TSP）分别显着降低了72.5％，35.8％和62.7％。PP / APP / HBPPA-Si复合材料具有更高的阻燃性和抑烟性，这归因于它们在冷凝和气相作用下均能有效发挥出色的协同作用。值得注意的是，具有热稳定的含P和Si的交联结构的高质量和高数量的焦炭残渣可以保护下面的聚合物材料免受进一步水解，并同时使挥发性燃料和热传递绝缘。此外，HBPPA-Si的弱极性硅烷壳层改善了APP在PP基体内的界面相容性，从而随着HBPPA-Si浓度的增加而增强了机械性能。