Toughening Effect of Strain-Induced Crystallites in Natural Rubber

Author :H. P. Zhang, J. Niemczura, G. Dennis, K. Ravi-Chandar, and M. Marder
Volume :102
Number :245503
Pages :1-4
Year :2009

We study fracture propagation in stretched natural rubber sheets. Experimental results in specimens
stretched less than 3.8 times show a monotonic increase in the crack speed with stretch and can be
explained by a numerical model based on neo-Hookean theory and Kelvin dissipation. In specimens
stretched more than 3.8 times, strain-induced crystallites act as reinforcing and toughening fillers and
significantly increase fracture resistance, like nanostructures in other polymeric or biological materials.
Consequently, as we increase the amount of stretch, fractures travel slower and slower, and eventually halt