Résumé
The objective of our work was to characterize natural rubber (NR) samples with different macromolecular structures by measuring Mooney viscosities (VR) at variable rotor speeds ≤2 rpm, called variable speed Mooney viscosity (MVS). Model samples of technically specified rubbers of constant Mooney viscosity (TSR5CV) were prepared with chosen specific clones. The structures of the samples were characterized by size-exclusion chromatography coupled with an online multi-angle light-scattering detector (SEC-MALS). Rheological properties of the samples were also characterized by a dynamic moving die rheometer. Measuring monoclonal model samples by MVS showed three types of VR flow curves. The VR at high rotor speed (2 rpm) was correlated with number-average molar mass (Mn), whereas VR at low rotor speed (0.05 rpm) was correlated with weight-average molar mass (Mw). Measuring MVS revealed the rheological behaviors of samples and enabled discrimination between samples with different macromolecular structures and should thus help in predicting processability