Stress-Strain Relation and Strain-Induced Crystallization of Natural Rubber

Stress-strain relations and strain- induced crystallization of varied crosslink structures, crosslink densities of vulcanized natural rubber, vulcanized synthetic poly-isoprene rubber and un-vulcanized natural rubber are compared by synchrotron X-ray. Upturns of stress and onset strains of strain-induced crystallization do not depend on each other. Vital element for the onset strain of SIC seem to be not crosslink but entanglement. The form of SIC may be bundle-like nuclei and extended chain crystal. SIC of rubber is close to flow induced crystallization (FIC) of polymer melt.