Surface modification mechanism of aramid fiber by AACH nanowire recasting and its enhanced modification of TPU

In order to improve the interfacial adhesion with matrix resin, the surface of aramid fibers was recast by surface growth of NH4[Al(OOH)HCO3] (AACH) nanowires. The morphology of aramid fibers before and after treatment was observed by scanning electron microscopy. The infrared and thermal stability of the fibers were tested and the mechanism of surface modification reaction was speculated. The effect of recasting modification on the mechanical properties and thermal stability of TPU resin was further studied. The results show that the roughness of aramid fibers increases obviously after surface recasting, but the thermal stability decreases and the thermal decomposition temperature decreases from 560 degrees C to 480 degrees C. At the same time, the interfacial state between surface recasted aramid fibers and TPU resin matrix was significantly improved and the mechanical properties of the composites were further improved. Compared with pure TPU resin, the tensile strength and modulus of the composites increased as 34.3% and 384.0%, respectively, but the elongation at break decreased from 1180.0% to 787.0%.