IN SITU FABRICATION OF CARBON FIBER/CARBON NANOTUBE HYBRID FOR PROMOTING THE FLAME RETARDANCY OF POLYPROPYLENE

摘要

A novel dense carbon fiber (CF)/carbon nanotube (CNT) hybrid was fabricated through catalytic carbonization of polypropylene (PP) by the combined catalysts of chlorinated CF (CF-Cl) and Ni2O3 to remarkably improve the flame retardancy of PP.The trace amount of chlorine radicals from the decomposition of CF-Cl promoted the degradation of PP radicals into hydrocarbons and aromatic compounds, while Ni2O3 catalyzed these degradation products into CNTs, which were aggregated into microscale spheres.Meanwhile, the macroscale CF-Cl acted as support for microscale CNT spheres to in situ form CF/CNT hybrid.The compact hybrid not only reduced the amount of flammable volatiles during combustion, but also prevented the diffusion of oxygen into PP matrix and volatile decomposition products out of PP and acted as a thermal shield for energy feedback from the flame.