# Ground Tire Rubber in the Sustainable Development of Flexible and Conductive Thermoplastic Polyurethane/Carbon Black Composites

## TL;DR

This paper explores using recycled tire rubber to create cost-effective, conductive materials for flexible electronics.

## Contribution

The study introduces a novel use of micronized ground tire rubber to enhance conductivity and reduce costs in thermoplastic composites.

## Key findings

- Adding 5–20 wt% micronized ground tire rubber reduces manufacturing costs by 5.6–22.6%.
- Electrical conductivity of composites increases from 11.7 to 33.8 S/m with higher tire rubber content.
- Laser-activated composites show potential as flexible sensors due to improved electrochemical properties.

## Abstract

Ground tire rubber (GTR) is composed of high-quality components; therefore, searching for new technologies for GTR recycling and upcycling is fully justified. In this work, the effect of micronized ground tire rubber content on the rheological, mechanical, thermal, and morphological properties, electrical conductivity, and electrochemical behavior of thermoplastic polyurethane/carbon black was investigated. The application of micronized ground tire rubber in the range of 5–20 wt% reduces the manufacturing cost by 5.6–22.6% and improves the electrical conductivity and electrochemical properties of composites. The results showed that higher contents of ground tire rubber increased the electrical conductivity of the studied materials from 11.7 to 33.8 S/m. This phenomenon is due to two factors: (i) additional carbon black present in GTR and (ii) phase separation that promotes local carbon-rich domains and facilitates conductive pathway formation. Electrochemical analysis revealed that the studied composites after laser activation can be used as flexible sensors. This research work confirms that using a ground tire rubber as a low-cost and valuable source of raw materials is a promising approach for the sustainable development of soft electronics.