Influence of conditions of catalytic growth of carbon nanostructures on mechanical properties of modified carbon fibres

An investigation has been made of the process of catalytic growth of carbon nanostructures on the surface of carbon fibres (CF) by chemical vapor deposition (CVD) using a protective carbon coat based on α 2 -fraction of coal-tar pitch. It is shown that the diminution of ultimate tensile strength of CF during the growth of the carbon nanostructures is associated with appearance defects on the fibre surface. It is found that the CF surface is filled uniformly by carbon nanostructures with preservation of the initial mechanical properties if the process is implemented for duration up to 30 min in the 700800°C range using a mixture of benzene and cyclohexane. Thanks to a combination of high stiffness and strength and low density, carbon fiber (CF) reinforced composites are widely used in high-technology industry and engineering, including in aviation, rocket engineering, and ship building. But use of carbon fibre reinforced plastics based on thermoreactive matrices in highly loaded structures is constrained in many cases by inadequate resistance to crack propagation, low shear strength, and possible foliation of the composite upon shock impact. The reason for this is often inadequate adhesion of the binders to the CF surface. Since precisely the strength of the fibre−polymer matrix interface determines the efficiency of stress transmission through the interface, the CF is often submitted to surface treatment. Much attention is being focused lately on surface modification of fibres by carbon nanostructures (CNS), carbon