Tough nanocomposites: the role of carbon nanotube type.

Unusually large deformation is observed in poly(methyl metacrylate) (PMMA) electrospun fibers under tension when multiwall or single-wall carbon nanotubes (MWCNTs and SWCNTs) are included as a second phase in the fibers. These distortions are virtually absent in pure PMMA fibers and stem from markedly different energy dissipation mechanisms and necking modes arising from the dissimilar nanotube morphologies. Thus, both nanotubes types are effective tougheners of PMMA fibers, with an advantage for MWCNTs over SWCNTs.