Study On The Thermal Conductivity Of Rubber Composite Filled With Cnts And CB

Heat conductive rubber promises huge application potential in aviation, aerospace, electronics, electrical appliances and so on. It has been a hot research orientation of the material field to fill carbon nanotubes into rubber to produce rubber composites with excellent heat-conducting property. Carbon black is often used in rubber industry as a kind of reinforcing filler. The addition of carbon black to rubber products will significantly improve the heat conductivity of rubber materials.In this research project, mechanical and solution blending were used to make the carbon nanotubes and carbon black fillers evenly dispersed in the natural rubber matrix. Besides, machinery and magnetic field were used respectively to make the carbon nanotubes directionally arranged in the natural rubber matrix. C hanges were made on the magnetic field intensity, the filling amount of carbon black, and the filling amount and type of carbon nanotubes, in an effort to study the effect of such changes on the heat-conducting property and mechanical property of natural rubber. Finally, centrifugation was used to make the carbon nanotubes particles aligned in silicone rubber, in a bid to probe into the change in heat conductivity coefficient of silicone rubber composites.The project showed: For the magnetic-aligning carbon nanotubes experiment, with the increase in magnetic field intensity, the heat conductivity coefficients of the natural rubber composites filled with magnetized magnetized carbon nanotubes and carbon black rose first and then fell, with the maximal value of 0.405W/(m?K). Compared with composites with unmagnetized carbon nanotubes, the composites with magnetized carbon nanotubes nearly rose b y once in heat conductivity coefficient. Where the magnetic field intensity came to 430 mT, the composites with 6%(volume fraction, the same below) carbon nanotubes and 10% carbon black rose by 0.296W/(m?K) in heat conductivity coefficient, compared with the composites without carbon black. However, the difference in heat conductivity coefficient between the two was only 0.061W/(m?K) when magnetic field was not introduced.In this project, carbon nanotubes/carbon black natural rubber composites were prepared through mechanical blending. With the increase in the filling amount of carbon nanotubes, the heat conductivity coefficient of composites rose. When the volume fraction of carbon nanotubes was 12%, the composites saw a maximal growth rate of 134.6% in heat conductivity coefficient, compared with the natural rubber. With the rise in the volume fraction of carbon black, the heat conductivity coefficient of composites went up gradually. Besides, the composites with aligned carbon nanotubes featured higher heat conductivity coefficient than the composites with unaligned carbon nanotubes. Where the volume fraction of carbon black rose to 20%, the rubber composites filled with aligned carbon nanotubes and carbon black increased by 90.78% in heat conductivity coe fficient, compared with the rubber composites without carbon black. The greater the filling amount of carbon black was, there was greater difference in heat conductivity coefficient between composites with aligned carbon nanotubes and those with unaligned carbon nanotubes.In this project, solvents were used to disperse the thermally conductive particles of carbon nanotubes into silicone rubber latex. Then directional mechanical agitation was conducted to prepare the test specimen of the silicon rubber comp osites filled with aligned carbon nanotubes. Where the volume fraction of carbon nanotubes remained at 2%, the heat conductivity coefficient along the aligned carbon nanotubes rose by 41.8%, compared with the condition where carbon nanotubes were not added. Where the filling amount came to 4%, the growth in heat conductivity coefficient slowed down. Where the volume fraction of carbon nanotubes rose to 6%, there was a growth of 24.9%, compared with the condition where there were 4% carbon nanotubes contained; however, a growth of 94.5% compared with the condition where there were no carbon nanotubes.