芳纶纤维表面改性及其对芳纶纸基材料机械性能的影响

The surface modification of aramid fiber and its effect on the mechanical strength of aramid paper-based material

针对芳纶短切纤维存在的表面光滑、呈化学惰性等缺陷,采用磷酸氧化、等离子体处理、多巴胺仿生修饰方法对纤维表面进行改性处理,对改性前后纤维的表观形貌和化学结构进行表征,并通过湿法成型制备相应的芳纶纸基材料.结果表明,改性后的纤维表面出现了高低不平的凹槽和刻蚀,纤维表面粗糙度增加,暴露出羟基和羧基等活性基团;磷酸处理和等离子体处理后制备的芳纶纸强度性能有所下降,多巴胺改性后制备的芳纶纸的强度性能有所提高,说明多巴胺改性赋予纤维一定的表面活性,使得纤维交织紧密,纤维间的结合强度提高,成纸性能变得优异.

According to the surface defects of smooth and chemically inert surface of aramid chopped fiber,the surface modification method such as phosphoric acid oxidation,plasma and dopamine biomimetic methods were used to modify the surface of aramid chopped fiber.The morphologies of modified fibers were characterized and a series of aramid paper based materials were prepared via wet forming process.The results showed the rugged grooves and surface etching appeared on the surface of fibers and the surface roughness increased.Some active groups such as hydroxyl and carboxyl were exposed.The mechanical strength of aramid paper based materials after phosphoric acid oxidation and plasma treatment decreased,the mechanical strength of paper with dopamine modification improved,which indicated dopamine modification endowed the fiber with surface activity,bonding fibers tightly and increasing the strength of paper.