Effect Of Reinforcing Materials On The Properties Of Nitrile Butadiene Rubber

(1) Two kinds of nitrle butadiene rubber (with different acrylonitrile conent, brand:1965, 3380)/organic montmorillonite (NBR/OMMT) composites were prepared by mechanical blending. The structure of the nanocomposites was characterized by XRD (X-Ray Diffraction) and TEM (Transmission Electron Microscope). The influence of OMMT content on the vulcanization properties was studied. The influence of the OMMT content and the acrylonitrile content on the properties of mechanical, hot air aging, processing, oil resistance, thermal stability of nanocomposites were also studied. XRD also showed that with the increasing of OMMT content (5～20 phr), interlayer spacing of the NBR/OMMT nanocomposite decreased gradually.The reinforcing mechanism of OMMT to the NBR rubber was compared with that of carbon black. With the increasing of the OMMT content, the tensile strength of NBR/OMMT nanocomposites was improved greatly. The reason was that the degree of crystallinity and orientation of rubber macromolecules was improved under tensile condition, which was due to the strong interaction between OMMT nanolayers with high specific surface area and rubber macromolecules. In conclusion, the reinforcing mechanism of OMMT was due to the adsorption of OMMT nanolayers to the rubber macromolecules.With the increasing of the acrylonitrile content, the tensile strength, elongation at break, tear strength, modulus at 100%, hardness, density, Mooney viscosity and compression set of NBR/OMMT nanocomposites increased. The properties of hot air aging, oil resistance and thermal stability were also improved.(2) Two kinds of NBR/carbon black blend composites with different acrylonitrile content were prepared by mechanical blending. The influence of different ratio of N774/N330 on the vulcanization properties was studied. The influence of the ratio of N774/N330 and the acrylonitrile content on the properties of mechanical, hot air aging, processing, oil resistance were also studied. The results showed that the properties of mechanical, hot air aging and oil resistance were improved and Mooney viscosity was increased by the synergistic effect of carbon black N774 and N330.With the increasing of the content acryloniturle, the scorch time (Ts2) and the cure time (T90) shortened. T90 of the NBR (1965) vulcanizate initially extended and then shortened after extend, while T90 of the NBR (3380) vulcanizate extended gradually.With the increasing of the content acrylonitrile, the tensile strength, elongation at break, tear strength, modulus at 100%, hardness, density and Mooney viscosity of NBR vulcanizate increased, while compression set decreased. The properties of oil resistance and hot air aging were also improved.