Dimensional and Thermal Reliability of Multi-Walled Carbon Nanotube Filled Natural Rubber Nanocomposites

Abstract

The exceptional mechanical and thermal properties, conceivable with carbon nanotubes (CNTs) make a distinction of them as excellent choices for natural rubber nanocomposite reinforcement. Nigeria, in recent years, has been awash with foreign prostheses, many of which fail to meet the criteria of the International Society of Prosthetics and Orthotics (ISPO) for developing countries. However, there are major marked gaps that make them susceptibility to premature failure and dimensional instability, caused by a high rate of water absorption in a humid environment; owing to the dynamic nature of human gait. This paper critically examines the effect of water absorption, thermogravimetric and dynamic mechanical properties, on carbon nanotube-reinforced natural rubber nanocomposite (NC) for prosthetic foot application. CNTs were synthesised via catalytic chemical vapour deposition (CCVD) technique and the NCs were produced by using an electrically heated hydraulic press. Thermogravimetric analysis (TGA), water absorption rate and dynamic mechanical analysis (DMA) of the nanocomposites were carried out with a view to comparing the various compositions used in this paper. Of the five NCs developed (NR/MWCNT-0, NR/MWCNT-3, NR/MWCNT-6, NR/MWCNT-9, NR/MWCNT-12 and NR/MWCNT-15), NR/MWCNT-3 (3 g of MWCNT in 100 g of natural rubber) showed the highest thermal stability of 260 °C, optimal water absorption rate of 0.1% and highest quality energy storage and dissipation capacity, as indicated by 2.239 DMA loss factor curve amplitude, hence giving it a comfortable edge over its existing counterparts. The results of the various analyses carried out indicated, therefore, that reinforcing natural rubber with multi-walled carbon nanotube offers a reliable alternative material for the prosthetic industry.