Sliding graft copolymer/nitrile butadiene rubber composites and its damping property

Sliding graft copolymer (SGC)/nitrile butadiene rubber (NBR) composites were prepared by blending NBR with presulfiding SGC. The effects of presulfiding temperature on internal structure and dynamic mechanical properties of the composites were investigated by DSC, rubber processing analyzer (RPA), TEM, FTIR, etc. The results show that the sea island structure forms:with SGC as the dispersed phase in NBR matrix. The intermolecular hydrogen bonds are formed between NBR macromolecule, leading to good compatibility and apparent interfacial interaction region. Compared with the pure NBR matrix, the glass transition temperature for SGC/NBR composites increase and the mechanical properties such as the tensile strength and elongation at break of composites increase significantly with stretch orientation because of the existence of the interfacial interaction region.Due to the diffusion and hydrogen bonding between SGC and NBR molecular chains, the internal rotation of the molecular chain σ single bond is hindered, so composites need to consume energy to overcome the resistance when rotating, resulting in significantly increase of loss factor. Especially, the damping property of composite with the SGC precured at 160℃ is best. The SGC/NBR composites exhibite excellent damping properties in the range of the vibration frequency and strain deformation of the building and could be expected to have important applications as a high damping seismic isolators.