Fabrication of mechanically robust and UV-resistant aramid fiber-based composite paper by adding nano-TiO2 and nanofibrillated cellulose

Abstract Aramid fiber-based composite paper is widely used as an engineering material that is often used in outdoor environments. This inevitably cause ultraviolet (UV) damage to aramid fibers. In this work, nanotitanium dioxide (nano-TiO 2 ) was introduced to endow the composite a good UV-resistance while nanofibrillated cellulose (NFC) was used to disperse and deposit TiO 2 nanoparticles onto aramid fibers by physical interaction. Firstly, TiO 2 nanoparticles were treated by (γ-aminopropyl) triethoxysilane to achieve abundant amino-groups (–NH 2 ), which can interact with hydroxyl groups (–OH) of NFC. The results showed that NFC can significantly suppress nano-TiO 2 aggregation and result in a well-defined core–shell structure of TiO 2 nanoparticles uniformly coated onto aramid fibers. Also, the bridge effect of NFC and the reinforcing effect of nano-TiO 2 benefit the mechanical properties the aramid/NFC/TiO 2 composite. The maximum tensile index (~ 16.42 N m/g) and maximum tearing index (~ 9.28 mN m 2 /g) of aramid/NFC/TiO 2 composites increase by ~ 43.4 and ~ 26.1% in comparison with the control sample (~ 11.45 N m/g and ~ 7.36 mN m 2 /g), respectively. Meanwhile, the aramid/NFC/nano-TiO 2 composite achieves a good UV-resistant property because of the dominant light-absorbing ability of well-dispersed TiO 2 nanoparticles. Therefore, our work presents a green and damage-free approach to achieve high-performance aramid fiber composite especially with great UV resistance. Graphical Abstract