Preparation Of Carbon Nanotubes/natural Rubber Composites By Ionic Liquid Modified Carbon Nanotubes

Due to its unique structure,carbon nanotubes have high strength,great toughness,and excellent electrical and thermal conductivity.However,due to the large aspect ratio of carbon nanotubes,high surface energy due to entanglement and large specific surface area is caused.As a result,the carbon nanotubes appear in agglomerated form and are difficult to disperse in the matrix,so it is very important to modify them.In this paper,under the action of mechanical grinding and shearing,non-covalent modification of multi-walled carbon nanotubes was carried out using ionic liquids,and an ionic liquid-modified multi-walled carbon nanotube(IL-MWCNT)was prepared.Natural rubber(NR)and natural rubber latex(NRL)were used as substrates and ionic liquid modified multi-walled carbon nanotubes were used as filler to prepare modified multi-wall carbon nanotubes/natural rubber(IL-MWCNT/NR)composites.The properties of different content,different kinds of ionic liquids and different contents of carbon nanotubes and unmodified carbon nanotubes/natural rubber composites were added.The interactions between carbon nanotubes and ionic liquids were studied by means of transmission electron microscopy,DSC,TGA and Raman methods.The microstructures of carbon nanotubes/natural rubber composites modified by ionic liquids were investigated by DMA,RPA and transmission electron microscopy.,Mechanical properties,fatigue resistance,and Payne effects are systematically studied.The results of the study are as follows:(1)The results show that under the effect of colloidal grinding,the ionic liquid and carbon nanotubes pass cation-? and ?-? conjugation,so that the ionic liquid can adhere to the surface of the multi-walled carbon nanotubes,thereby the ionic liquid.Non-covalent modification of multi-walled carbon nanotubes was performed,and ionic liquid-modified carbon nanotubes were obtained after sonication.DSC,TGA and other characterizations showed that there was a certain interaction between the ionic liquid and the carbon nanotubes.Transmission electron microscopy showed that the carbon nanotubes were uniformly dispersed,the agglomeration was significantly reduced,and they could stably exist in water.The ionic liquid modified carbon nanotubes significantly improving the dispersion of nanotubes.(2)Transmission electron microscopy showed that ionic liquid-modified carbon nanotubes can be stably dispersed in the natural latex matrix.The presence of ionic liquids reduces the glass transition temperature Tg of IL-CNT/NRL composites.Through comparison of the experimental results,it is found that carbon nanotubes are more likely to form a uniform packing network structure in the rubber matrix after the ionic liquid is modified.The vulcanization curve shows that the vulcanization rate of the IL-CNT/NRL composites with ionic liquids decreases,and the fatigue life of the ionic liquid-modified carbon nanotubes natural latex composites reaches the maximum when the ionic liquid is added at 1 phr,and the addition of IL-CNT/ is continued.The fatigue life of NRL is continuously declining.For composite materials with carbon nanotubes added as a variable,the fatigue life decreases with the increase of carbon nanotubes.(3)Studies have shown that the ionic liquid modified carbon nanotubes natural rubber composites have lower vulcanization speeds and can form a uniform filler network.At the same time,in the presence of ionic liquids,the glass transition temperature of IL-CNT/NR composites decreases,and losses occur.With the increase of modulus,the fatigue life of modified natural rubber composites did not decrease significantly at 1 phr,and the increase of ionic liquid content decreased the fatigue life of rubber and was lower than the fatigue life of natural latex composites under the same conditions.