The Study On The Structure And Dynamic Mechanical Properties Of Multi-walled Carbon Nanotubes/silicone Rubber Composites

This thesis mainly studies the properties and structures of different reinforcing filling system, especially carbon nanotubes, on silicone rubber.In this paper, we selected carbon nanotubes, carbon black, and silica as filler. We prepared silicone rubber/filler materials, and studied the mechanical properties of the composites, vulcanization processing performance, thermodynamic properties, dynamic mechanical properties and microscopic structure.The results show that:1. With the increased amount of three kinds of fillers, the scorch time goes to ascend, and the processability of composites can be improved. In addition, Carbon nanotubes stress softening effect is more apparent than carbon black and silica. When talking about the meaning of stress softening effect, carbon nanotubes on silicon rubber reinforcing is higher than carbon black and silica, we think the crosslinking degree of the composite is improved significantly.2. Along with the increase of the three kinds of fillers, the storage modulus, loss modulus and loss factor and torque of the composite materials are obvious rising, and they all has a significant decline when the deformation reaches a certain degree, namely Payne effect.3. Three kinds of fillers can significantly improve the mechanical strength of silicone rubber, but carbon nanotubes has the best reinforcing effect, followed by silica and carbon black.4. Three kinds of filler material to improve the thermal stability of the oxygen has significant effect of silicone rubber, the thermal resistance of composite filled with carbon nanotubes is small, heat conduction performance is good, namely has the best thermal stability of oxygen, silica and carbon black is a bit poor.5. Through the study of dynamic mechanical properties of composite materials,we found that when carbon nanotube filling quantity is small, the energy storage modulus of the composite has little change with the increase of strain amplitude.But with carbon nanotube filling quantity increase, there is an obvious Payne effect, the effect of the volume fraction of carbon nanotubes in about 5%, which is completely different from carbon black and silica in filling rubber network structure formed in the volume fraction of 10% to 15%, proved that the composite materials in some form of network structure formed by carbon nanotubes, the breaking and rebuilding of the network structure leading to a fall in energy storage modulus of the nonlinear.6. 5phr, 10 phr, 20 phr, 30 phr carbon nanotubes can be evenly dispersed in the silicone rubber matrix, and they didn’t happen obvious aggregation. 20 phr carbon black and silica can be dispersed in the silicone rubber matrix, but they did not dispersed homogeneously as carbon nanotube. Carbon nanotubes have a special affinity packing with silicone rubber, and they can be evenly dispersed in the silicone rubber matrix.