Nanocomposites toughness

Crack toughness behavior of MWCNT/polycarbonate nanocomposites was also reported (Xiao et al., 2004 Foster et al., 2005). When 2 wt.% MWCNTs was added into the composites, the resistance to crack propagation was markedly increased compared to pure Polycarbonate. At 4 wt.% MWCNTs, a tough-to-brittle transition has been observed. The attack of crack initiation needs shorter time for nanocomposites with 4 wt.% MWCNT compared to the composites with 2 wt.% MWCNTs, which supports that a tough-to-brittle transition exists in these nanocomposites. 

Satapathy BK, Weidisch R, Potschke P, Janke A (2005). Crack toughness behaviour of multi-walled carbon nanotube (MWNT)/polycarbonate nanocomposites. Macromol. Rapid Commun. 26 1246-1252. 

It was found that dramatic improvements in toughness, strength, creep strength and thermoresistance could be achieved by incorporating nano-SiC dispersion in a microcrystalline matrix. Subsequently, similar improvements were found in other nanocomposites [1],... 

Hoffman, M., Rodel, J., Stemitzke, M. et al., Fracture toughness and subcritical crack growth in alumina/silicon carbide nanocomposites , Fracture Mechanics of Ceramics, 1996, 12 179. 

Xia, Z., Curtin, W.A., Sheldon, B.W., Fracture toughness of highly ordered carbon nanotube/alumina nanocomposites, J. Eng. Mater. Tech., 2004, 126(3) 238. 

Mishra, R.S., Mukheijee, A.K., Processing of high hardness-high toughness alumina matrix nanocomposites, Mater. Sci. Eng. A, 2001, 301 97. 

The unique two-phase structures of polyurethane that offers the elasticity of rubber combined with the toughness and durability of metal make them one of the most extensively studied and frequently used materials in carbon nanotube related nanocomposites. The main difficulty in developing CNT based polyurethane nanocomposites was how to achieve uniform and homogeneous CNT dispersion. Further investigations on the interactions between carbon nanotubes and two-phase structures are critical for the wider applications of carbon nanotube/polyurethane composites. 

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