Novel Slide-Ring Material/Natural Rubber Composites With High Damping Property

Earthquake is a kind of unpredictable natural disaster with characteristics of high incidence and strong destroying. Improving the anti-seismic strength of buildings is an effective approach to protect life and reduce economic loss. Isolation bearing is an impor tan t device to reduce the seismic force transmitted to buildings with functions of restoring force and energy dissipation. All the desirable mechanical properties make NR to be the favored matrix material to meet the requirement of isolation bearing. But the macromolecule chain of natural rubber is submissive, which causes less internal friction between the molecules and small dissipation factor. And eventually, this would affect the effects of the damping seriously. Considering that, many additional damping devices such as hydraulic dampers, steel bar dampers or friction dampers is still required for energy dissipation.In recent years, slide-ring(SR) materials have draw an intensive attention because of its supramolecular architecture with topological characteristics. The key feature of SR different from conventional rubber material is that the cross-linking junction fixed on a-CD can freely slide and along the backbone. Because of these effects, SR have the special properties of low EO, small compression set, small stress relaxation, and a large loss tan gent in the viscoelastic profile in a wide frequency range.In this paper, "slide-ring(SR) material" was firstly used for high damping composites. It was acting as a high damping phase dispersed in natural rubber(NR) matrix to prepare NR/SR composites. Epoxidized natural rubber(ENR) was acting as compatibilizer to prepare NR/ENR/SR composites. The structural and properties of the NR/SR and NR/ENR/SR composites were systematically investigated by using atomic force microscope (AFM), tensile testing, dynamic mechanical thermal analyzer (DMTA), rubber processing analyzer (RPA) and wide angle X-ray diffraction (WAXD). The results showed that the SR phase could be uniformly dispersed in NR/SR composites with phase size of 5-10μm. The phase size of SR in NR/ENR/SR composites is less than 3 μm. And the damping factor of NR/SR composites increased from 0.1 to 0.4 at 0℃. The ENR used in the composites can also improved the damping factor in room temperature zone. And the damping factor of NR/ENR/SR composites increased to 0.75 at 0℃. The tensile strength of NR/SR composites is 12MPa and the tensile strength of NR/ENR/SR composites is 13MPa. The frequency and strain sweeping for the composites were investigated by rubber process analyzer (RPA) according to the British S tan dard for seismic protection elastomeric isolators. Stretch hysteresis was used to study the energy dissipation of composites in simulated earthquake environment and establish relationship with damping factor. Synchrotron wide-angle X-ray diffraction (WAXD) was used to study the strain-induced crystallization of composites. The results indicated that SR phase can accelerate the start of crystallization process, but the ultimate crystallinity is decreased. With the adding of ENR, NR undergo crystallization according to its own rule.