Carbon Nanotube-Based Thermoplastic Polyurethane-Poly (methyl methacrylate) Nanocomposites for Pressure Sensing Applications

Abstract

We have synthesized unique flexible pressure-sensitive nanocomposites by means of a solution mixing method, by adding multiwalled carbon nanotubes (MWCNTs) into a thermoplastic urethane (TPU) matrix along with poly (methyl methacrylate) (PMMA) microbeads of various sizes. The influence of the various PMMA bead sizes on the pressure sensing properties of the nanocomposites was studied over a range of pressures. The PMMA microbeads were used to achieve an early percolation threshold at low loadings of MWCNTs. We used scanning electron microscopy to study the nanocomposites' morphology, and conducted differential scanning calorimetry analyses to investigate their thermal properties. The nanocomposites' electrical and thermal conductivities were also measured under various applied pressures. The nanocomposites displayed repeatable electrical responses under various applied pressures, demonstrating their suitability for use as pressure sensing materials. The proposed material is an ideal candidate for use in the preparation of pressure-sensitive devices. (C) 2016 Society of Plastics Engineers