Piezoresistive and mechanical Behavior of CNT based polyurethane foam

Abstract

Carbon nanotubes (CNT) embedded into a polymeric foam demonstrate an enhancement in electrical and mechanical properties of the final nanocomposite. The enhanced material with new characteristics, e.g., piezoresistivity, can be substituted with the traditional metallic material to design sensors, switches, and knobs directly into a single multifunctional component. Research activities in this field are moving towards a mono-material fully integrated smarts components. In order to achieve this goal, a simple method is developed to produce piezoresistive polyurethane/CNT foams. The novelty consists in applying the dispersion of CNT considering industrial production constrains, in order to facilitate its introduction into a common industrial practice. Three kinds of PU-CNT foam have been prepared and tested: PU-CNT 1.5%, PU-CNT-COOH 1.0%, and PU-CNT-COOH 1.5%. Polyurethane with CNT-COOH showed an insulating-conductive transition phenomenon when the foam reaches the 80% of its compression strain with a Gauge factor (Gf) of about 30. Instead, PU-CNT showed conductivity only at 1.5% of filler concentration and a steady piezoresistive behavior with a Gf of 80. However, this samples did not show the insulating-conductive transition. Having improved the electromechanical properties of final nanocomposite polyurethane foam demonstrates that the proposed method can be applied differently for design sensors and switches.

Thermal/Electrical Properties and Texture of Carbon Black PC Polymer Composites near the Electrical Percolation Threshold

“…If the composite material becomes electrically conductive, it can be used in new applications, in which electrical properties are required, such as antistatic or static dissipation, conductive and electromagnetic shielding materials [4]. Among the carbon fillers to be dispersed in polymers, CNTs and graphene have the most notable effect on electrical conductivity, with an electrical percolation threshold ranging between 1 and 4 wt.% [6][7][8][9][10][11][12], while a higher filler loading (c.a. 4-15 wt.%) is usually required to obtain an electrical percolated network with graphite-based materials (graphite flakes, graphite nanoplatelets, expanded graphite, nanographite) [13][14][15], carbon fibers [16], and carbon black [11,17,18].…”

The status and perspectives of nanostructured materials and fabrication processes for wearable piezoresistive sensors

“…Owing to the new structure, these PRSs can monitor both short and long human movements that derive from the nano crack joint sensing mechanism and physical contact of conductive interconnected networks. De Meo et al ( 2020 ) used CNT embedded into a polymeric foam (PU) that showed an increase in electrical and mechanical properties. They manufactured three kinds of PRSs based on PU-CNT foam, (i) PU-CNT 1.5%, (ii) PU-CNT-COOH 1.0%, and (iii) PU-CNT-COOH 1.5%.…”

Otomotiv Sektöründe Kullanılan MWCNT Katkılı Poliüretan Nanokompozitlerin Eğilme Hasarının İncelenmesi

“…Science and industry are interested in polyurethanes (PU) because of their advantageous physical and chemical properties and the possibility of changing their structure depending on the intended use. Due to the fact that polyurethanes are one of the most versatile materials in the world today, they have many uses such as wall insulation, thermoplastic polyurethane roofs and floor coatings, automotive interior coatings, aerospace coatings, adhesives, fillers, and medical devices [2][3][4].…”