An inherent flame-retardant PA6 (FR-PA6) containing polydiphenylsiloxane (PDPS) was synthesized under the action of ethylene glycol (EG) via a facile “2-step” bulk polymerization. Inspiringly, EG acted not only as a ‘chain-linker’ to connect PA6 oligomer with PDPS moiety but also as a charring agent to increase the charring capacity of FR-PA6 after combustion. The prepared FR-PA6 reached 28.3% of limiting oxygen index (LOI), and passed the V-0 level of UL94 test with suppressed melt-dripping. After investigating the char residues and pyrolysis volatiles of FR-PA6 after combustion, the formation of silicon-rich protective layer was proved to be the essential factor to increase the flame retardancy of FR-PA6 via reducing the diffusion of pyrolysis volatiles, restricting the heat transfer and mass loss as well as preventing polymer melts from dripping. This work thus makes a worthwhile contribution to the development of FR-PA6 by offering a novel route that is easily accessible to industrial fabrication.

在乙二醇（EG）的作用下，通过简便的“两步”本体聚合合成了一种固有的包含聚二苯基硅氧烷（PDPS）的阻燃性PA6（FR-PA6）。令人鼓舞的是，EG不仅充当了将PA6低聚物与PDPS部分连接的“链连接剂”，而且还充当了炭化剂，以提高燃烧后FR-PA6的炭化能力。所制备的FR-PA6达到极限氧指数（LOI）的28.3％，并通过了UL94测试的V-0水平，并抑制了熔滴。在研究了燃烧后FR-PA6的焦炭残留物和热解挥发物后，富硅保护层的形成被证明是通过减少热解挥发物的扩散来提高FR-PA6阻燃性的重要因素，限制传热和质量损失，并防止聚合物熔体滴落。因此，这项工作通过提供一种易于工业制造的新颖途径，为FR-PA6的开发做出了有价值的贡献。