Synchrotron WAXS Studies of stretched Natural and Synthetic Rubber Networks showing an Upturn in Stress-Strain Curves

摘要

Natural rubber (NR) displays very distinct stress-strain curve with an upturn in the stress at high elongations while most synthetic rubbers do not. This behavior has been associated with strain induced crystallization. Here we show that three non-crystallizing weak synthetic rubbers, i.e. BR, NBR and SBR, could be reinforced in such a way that their stress-strain curves are very similar to that of unfilled NR. Synchrotron wide angle X-ray scattering (WAXS) was used to follow the development of the internal structure during stretching of these rubbers. WAXS patterns at different levels of strain were recorded and analyzed. Results on azimuthal scans of the patterns will be presented and discussed in relation to limited chain extensibility.