Study On Preparation, Structures And Properties Of Molybdenum Disulfide/Rubber Composites

This paper brings forward two innovative routes to prepare MoS2/rubber composites, aiming at improving the mechanical properties, wear properties and lowering the friction coefficients of rubber composites at the same time. One is mixing then co-coagulating of rubber latex and MoS2 single layers aqueous suspension. The other is directly blending of organic modified MoS2 into rubber, because the organic modification of MoS2 should weaken the adhesion between layers and make it easier to separate them by shear force.The first part is a systematic study on composites prepared by directly blending. By using XRD, SEM and TEM, we find the average size of MoS2 in rubber is in microns, and MoS2 keeps its lamellar structure. With more MoS2, the modulus at 100% and 200% elongation of composites increase steadily. However, at high strain, especially incarbon black reinforced composites, the weak interfacial adhesion will cause collapse of materials, which hurt the overall mechanical properties of composites. Using MHK-500 ring-on-block tribometer, we measure the friction coefficients of composites against smooth surface of steel and find it decreases when increasing the loading of MoS2, which is probably due to the sliding of MoS2 layers against each other on the interface of rubber and steel, since it is observed that the layers of MoS2 on the interface is oriented in the direction of shear force. In spite of that the friction coefficients of composites are reduced by adding MoS2, the wear resistance performance of composites still decreases due to poor interfacial adhesion between M0S2 and NBR matrix.The second part is study on the composites prepared by co-coagulating. Mainly we characterize its structures by XRD, SEM and TEM, and look into the effects on the procedure provided by utilizing different kinds of surfactants and also starch. We find that MoS2 disperses much better in rubber matrix by co-coagulating than by directly blending. The average dimension of MoS2 particles in composites by co-coagulating is around 1μm~2μm, and TEM pictures show clearly there are even some nano-particles of MoS2. The interfacial adhesion between MoS2 and rubber gets better. And MoS2 keeps its lamellar structure which is good for retaining its low friction coefficients. Using XRD and 13C-NMR, we conclude that the compounds interacted...