The Improvement of Wettability, Mechanical and Thermo-mechanical Performances of PBO Fiber/Epoxy Composites by Adding Reactive Carbon Nanotubes

A kind of reactive multi-walled carbon nanotubes (r-MWNTs) was prepared and incorporated in an epoxy matrix. Then the epoxy matrix containing 0.5 wt.% r-MWNTs was reinforced by poly-p-phenylene benzobisthiazole (PBO) fibers and the NOL-rings were prepared on a filament winding machine. The wettability of the uncured epoxy was evaluated by measuring the surface energy and viscosity. It was demonstrated that the epoxy with r-MWNTs exhibited much better wettability than that of pristine epoxy. After adding 0.5 wt.% r-MWNTs, the tensile strength, tensile modulus, elongation and interlaminar shear strength (ILSS) of NOL-rings demonstrated an enhancement of 11.02%, 1.86%, 16.52% and 61.1%, respectively, compared to the pristine epoxy composites. In addition, scanning electron microscopy (SEM) studies revealed that the addition of r-MWNTs could significantly improve the interfaces bonding between PBO fiber and epoxy matrix. The dynamic mechanical analysis results also showed that the glass transition temperature of the composites increased by about 5 °C after the addition of 0.5 wt.% r-MWNTs.