Reinforcement effects of vapour grown carbon nanofibres as fillers in rubbery matrices

The reinforcement of rubbery matrices by vapour grown carbon nanofibres (VGCFs) is studied in the case of a rubbery epoxy and a styrene butadiene rubber (SBR). In the case of epoxy, the VGCF were introduced in the hardener and blended with the prepolymer. Nanocomposites were produced by subsequent polymerization. For the second matrix, samples were prepared by casting of a mixture of SBR latex and a water suspension of VGCF. Evaluation of mechanical performances revealed a linear increase of the modulus measured above and below the glass transition temperature for nanofibre content up to 10 wt%. This increase is low, but in good agreement with the estimation based on mechanical coupling models. In the case of epoxy matrix, the ultimate stress and strain are largely increased, even for very low fibre content (i.e. 1 wt%). However, this improvement is not observed in the case of nanocomposites based on SBR matrix, due to the non-optimized dispersion of the fibres.