Effect of functionalized multi-walled carbon nanotubes on physicomechanical properties of silicone rubber nanocomposites

Abstract

Ethyl-4-aminocinnamate functionalized multi-walled carbon nanotubes–reinforced silicone rubber nanocomposites were developed by means of compounding (two roll-mill) and molding (compression). Meanwhile, multi-walled carbon nanotubes were synthesized using a catalytic chemical vapor deposition technique and functionalized using ethyl-4-aminocinnamate. The as-synthesized and functionalized multi-walled carbon nanotubes were subjected to Raman spectroscopy, Fourier-transform infrared spectroscopy, field emission scanning electron microscope, and transmission electron microscopy to know the presence of the functional group with its shape and size. Further, silicone rubber nanocomposites were subjected to study its mechanical (tensile strength, Young's modulus, and elongation at break), thermal (stability), and physical (swelling index and hardness) properties. The amount of loading of functionalized multi-walled carbon nanotubes was from 0 to 1 wt%. It was observed that with the increase in the amount of functionalized multi-walled carbon nanotubes loading, the properties were found to be increased. This improvement was due to uniform dispersion with the alignment of functionalized multi-walled carbon nanotubes inside the rubber matrix. Moreover, this improvement was due to weak functionalizing materials which make the surface smooth and glossy so as to facilitate uniform dispersion of materials. Also, thermal stability was found to be increased due to shifting of heat uniformly throughout the rubber matrix. Certainly, it reduces the swelling indices of silicone rubber as the chains are closely packed which does not allow a solution to get penetrated. This improvement in properties of silicone rubber nanocomposites was reflected from field emission scanning electron microscope, which shows uniform dispersion with the alignment of functionalized multi-walled carbon nanotubes inside the rubber matrix.