Comparative Study on Strain-Induced Crystallization Behaviours of Sulphur cross-linked Guayule Natural Rubber and Synthetic Isoprene Rubber

摘要

Strain-induced crystallization (SIC) behaviours of sulphur cross-linked guayule natural rubber (S-GR) and synthetic isoprene rubber (S-IR) were investigated using quick in situ simultaneous synchrotron time-resolved wide-angle X-ray diffraction/tensile measurement at SPring-8. Higher contents of oriented amorphous segments at low strain and crystallinity in S-GR were detected than in S-IR. This difference was ascribable to the presence of non-rubber components and higher cis content in S-GR than S-IR. Aggregates of non-rubber components may play a role in physically cross-linking polymer to accelerate the SIC in S-GR. S-GR and S-IR had comparable crystallite size and volume upon stretching, but the number of crystallites in the former was about twice than in the latter, particularly at large deformation.