It is a great challenge to achieve efficient flame retardance with no mechanical deterioration to polymers. In this study, novel sandwich-like cobalt borate nanosheets-molybdenum disulfide (CoBi-MoS₂) hybrids are synthesized by a facile aqueous-phase synthesis approach at room-temperature, and employed as nanofillers for PAN fiber. The amorphous CoBi nanosheet with surface Lewis pairs and potential flame-retardant characteristics acts as interfacial compatibilizer and cooperative flame-retardant, enabling simultaneous improvement in both flame-retardant and mechanical properties of 2 wt% CoBi-MoS₂/PAN composite fiber. Compared with pure PAN fiber, the peak heat release rate, peak smoke production rate and peak CO production rate of 2 wt% CoBi-MoS₂/PAN composite fiber are decreased by 46.2%, 45.7% and 62.9%, respectively. The gaseous and condensed phase analysis reveals that the catalytic redox activity, cross-linked charring and physical barrier effect of the CoBi-MoS₂ are responsible for the flame-retardant enhancements of PAN composite fiber. Simultaneously, the 2 wt% CoBi-MoS₂/PAN composite fiber exhibits a 58.7% and 49.1% improvement in tensile strength and elongation at break compared to pure PAN fiber.

实现有效的阻燃性而又不对聚合物造成机械破坏是一个巨大的挑战。在这项研究中，新型的三明治状硼酸钴纳米片-二硫化钼（CoBi-MoS ₂）杂化物通过一种简便的水相合成方法在室温下合成，并用作PAN纤维的纳米填料。具有表面路易斯对和潜在阻燃特性的无定形CoBi纳米片充当界面增容剂和协同阻燃剂，可同时提高2 wt％CoBi-MoS ₂ / PAN复合纤维的阻燃性和机械性能。与纯PAN纤维相比，CoBi-MoS ₂的峰值放热率，峰值烟雾产生率和CO峰值产生率/ PAN复合纤维分别降低了46.2％，45.7％和62.9％。气相和凝聚相分析表明，CoBi-MoS ₂的催化氧化还原活性，交联炭化和物理屏障作用是PAN复合纤维阻燃增强的原因。同时，与纯PAN纤维相比，2wt％的CoBi-MoS ₂ / PAN复合纤维表现出58.7％和49.1％的拉伸强度和断裂伸长率的改善。