Aramid nanofibers (ANFs) are outstanding mechanical enhancers of polymers because of the high strength and thermal stability, which also can be processed into macro films through vacuum filtration. However, it is difficult for other additives to improve the mechanical performances of ANFs films except carbon nanotubes (CNT). In this article, polyvinyl alcohol (PVA) and sodium borate (SB) were served as additives to synergistically improve the mechanical performances of ANFs films. It is found that the formed ANFs-PVA-SB ternary composite has a tensile strength of 279.5 MPa and a toughness of 35.7 MJ·m⁻³, which are 1.4 and 2.2 times higher than those of neat ANFs films. The high strength is mainly resulted from the fortified hydrogen bonding and physical intertwining between PVA and ANFs, and the formed covalent bonds between PVA and SB, while the high toughness is mainly caused by the soft PVA.

芳族聚酰胺纳米纤维（ANFs）由于具有高强度和热稳定性而成为出色的聚合物机械增强剂，也可以通过真空过滤将其加工成大薄膜。但是，除碳纳米管（CNT）以外，其他添加剂很难改善ANFs膜的机械性能。在本文中，聚乙烯醇（PVA）和硼酸钠（SB）被用作添加剂，以协同提高ANFs膜的机械性能。发现形成的ANFs-PVA-SB三元复合材料具有279.5MPa的拉伸强度和35.7MJ·m ^-3的韧性。分别是纯ANFs薄膜的1.4和2.2倍。高强度主要是由于PVA和ANF之间加强的氢键键合和物理缠结，以及PVA和SB之间形成的共价键，而高韧性主要是由柔软的PVA引起的。