Role of strain rate in the strain-induced crystallization (SIC) of natural and synthetic isoprene rubber

The role of strain rate ( $${\it{\dot \varepsilon }}$$ e ) in the strain-induced crystallization (SIC) of vulcanized natural rubber (NR) and synthetic isoprene rubber (IR) was studied using in situ wide-angle X-ray scattering (WAXS) (synchrotron X-ray radiation). We developed homemade extension equipment and coupled it with the synchronized time-resolved X-ray detector system. The nucleation rate (I) was determined for a wide range of $${\it{\dot \varepsilon }}$$ e values (0.0075 s−1–330 s−1) based on the increase in the scattering intensity (IX) as a function of time (t). We found that I is proportional to $${\it{\dot \varepsilon }}$$ e ( $$I \propto \dot \varepsilon$$ I ∝ e ). Based on this result, we concluded that $$\dot \varepsilon$$ e plays an important role in the kinetic mechanism of the SIC of NR and IR.