• Sahraeeazartamar, Fatemeh

Abstract

The addition of an organo-modified nanoclay to a carbon-based electrically conductive self-healing composite shows a synergistic improvement of both the electrical conductivity and self-healing ability of the formed hybrid composites. The effect on the electrical, viscoelastic and self-healing properties was studied for Diels-Alder-based reversible polymer networks with a maleimide-to-furan stochiometric ratio of 0.6, with different loadings of carbon black Ensaco 360G and nanoclay Cloisite 15A. The study was performed to optimize the content of carbon black and Cloisite 15A to achieve the best combination of electrical and self-healing properties by exploiting the synergistic effect of hybrid fillers. Hybrid composites were prepared with CB360G contents from 5 wt.% to 15 wt.% and nanoclay loading up to 1.5 wt.%. The percolating network of conductive particles led to the decent electrical conductivity of the order of 1 S m-1 in composites around 7.5 wt.% carbon black. It was concluded that depending on the carbon black content, the addition of the nanoclay can improve the electrical, mechanical, and rheological properties of composites synergistically. More importantly, the presence of Cloisite 15A increased the mechanical healing efficiency of the polymer composites after healing at 90 oC for 1 hour. Finally, the electromechanical properties of the selected hybrid composite with the best combination of two fillers were studied for sensor applications. Self-healing strain sensors show a positive piezoresistive response from 20% strain up to their failure. These promising results suggest the use of studied electrically conductive and self-healing hybrid composites for deformation and damage sensing applications in soft robotics.

Topics

• polymer
• Carbon
• composite
• electrical conductivity