芳纶沉析纤维-多巴胺/聚酰亚胺-酚醛树脂复合膜的力学及摩擦磨损性能

以聚酰亚胺（PI）纤维和酚醛树脂（PF）为基体，通过对PI纤维表面进行多巴胺（PDA）修饰，并引入芳纶沉析纤维（AF）作为增强体，采用湿法成型和热压固化技术制备了15wt% AF和7.5wt% PDA的AF-PDA/PI-PF复合膜，重点研究了AF的添加和PDA改性修饰对PI-PF复合膜力学性能和摩擦磨损性能的影响，并探讨了其磨损机制。研究结果表明:当添加AF并对PI纤维进行PDA改性时，AF-PDA/PI-PF复合膜的应力为47.54 MPa，抗张指数为56.91 Nmg-1，层间结合强度为1 265.6 Jm-2，相比PI-PF复合膜分别提高了33.65%、41.67%和64.11%；磨损率为1.01×10-4 mm3J-1，约降低了34.84%，其磨损机制主要为黏着磨损。这是由于PI纤维与AF可形成"互穿网络"结构，此外，PDA对PI纤维的化学改性处理可增加PI纤维表面活性，AF和PDA对提高PI纤维与树脂间的界面结合力及AF-PDA/PI-PF复合膜的力学性能和摩擦磨损性能起到协同作用。 

Mechanical and friction and wear properties of aramid fibrid-polydopamine/polyimide-phenolic resin composite films

The aramid fibrid-polydopamine/polyimide-phenolic resin(AF-PDA/PI-PF)composite films with15 wt% AF and 7.5 wt% PDA were prepared by wet forming and hot-pressing curing technique using PDA modified PI fiber and PF as the matrix with the introduction of AF as reinforcement.The effects of the addition of AF and PDA modification on the mechanical properties and friction and wear properties of PI-PF composite films and wear mechanism were mainly studied.The results show that when adding AF and using PDA modified PI fiber simultaneously,the stress,the tensile index and the interlayer bonding strength of AF-PDA/PI-PF composite films are47.54 MPa,56.91 N·m·g^-1 and 1 265.6 J·m^-2,respectively,which increase by 33.65%,41.67%and 64.11%compared with PI-PF composite films.The wear rate of AF-PDA/PI-PF composite films is 1.01×10^-4 mm^3·J^-1,which is 34.84%lower than PI-PF composite films.The main wear mechanism of AF-PDA/PI-PF composite films is proposed to be adhesive wear.The PI fiber and AF can form "interpenetrating networks" structure,and the PDA modification of PI fiber improves the surface activity of PI fiber,which plays a synergistic role in improving the interfacial bonding strength between PI fiber and PF,as well as the mechanical properties and friction and wear properties of AF-PDA/PI-PF composite films.