Flame‐retardant polyamide 6 (PA6) was prepared by an inorganic‐organic composite (MCN or MgO/g‐C₃N₄) synthesized by incorporating magnesium oxide (MgO) combined with graphitic carbon nitride (g‐C₃N₄). As compared to g‐C₃N₄, MCN possessed a laminate structure, more holes, and a larger specific surface area. The addition of MCN could effectively improve the flame retardancy and mechanical properties of PA6 due to its better compatibility and dispersion in the PA6 matrix. When the addition of MCN was 20 wt%, the vertical combustion performance of the PA6/MCN sample reached flammability rating V‐0 (UL‐94) and the limiting oxygen index (LOI) was up to 32.1%. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealed that the introduction of MCN efficiently enhanced thermal stability of PA6. The morphologies of the char residue observed by scanning electron microscopy (SEM) verified that MCN promoted the formation of sufficient, compact, and homogeneous char layers on the composite's surface during burning. Thus led to increase the char layer strength and improve the flame retardancy of PA6. The thermogravimetric analysis/infrared (TG‐IR) revealed the gas‐phase retardancy mechanism of MCN. Compared with PA6/g‐C₃N₄, PA6/MCN showed better mechanical properties in terms of flexural strength and tensile strength.

中文翻译：

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通过结合MgO和g-C3N4制备阻燃聚酰胺6

阻燃聚酰胺6（PA6）由无机-有机复合物（MCN或MgO / g-C ₃ N ₄）合成而成，该复合物是通过结合氧化镁（MgO）和石墨氮化碳（g-C ₃ N ₄）合成的。与g‐C ₃ N _4相比，MCN具有层压结构，更多的孔和更大的比表面积。MCN的添加由于其在PA6基质中的更好的相容性和分散性而可以有效地改善PA6的阻燃性和机械性能。当MCN的添加量为20 wt％时，PA6 / MCN样品的垂直燃烧性能达到可燃性等级V-0（UL-94），极限氧指数（LOI）高达32.1％。热重分析（TGA）和差示扫描量热法（DSC）的结果表明，MCN的引入有效地增强了PA6的热稳定性。通过扫描电子显微镜（SEM）观察到的焦炭残留物形态证实，MCN在燃烧过程中促进了复合材料表面上充分，致密且均匀的焦炭层的形成。因此导致增加了炭层的强度并提高了PA6的阻燃性。热重分析/红外（TG-IR）揭示了MCN的气相延迟机理。与PA6 / g‐C相比₃ N ₄，PA6 / MCN在抗弯强度和拉伸强度方面显示出更好的机械性能。