I was recently reading about Carbon Nanotubes having extremely high Young's moduli, as well as high Tensile Strength, making them very interesting fibers. However, when I read this I wondered what was behind these great properties. After doing some searching, I found that it has to do with the sp2 bonds the carbon atoms make, which are the (one of the?) strongest chemical bonds atoms can make. Moreover, a paper mentioned that the high degree of curvature might also play a role here.
But how exactly do these strong bonds and high curvature lead to a high Young's modulus, and a high tensile strength? What does curvature have to do with either of these two?
I would be very happy if someone could give me a somewhat qualitative argument, as to why these fibres have these properties. If it is possible to point me towards the theory section of a paper that discusses this, that is also perfectly fine.