On the Use of Mechano-Chemically Modified Ground Tire Rubber (GTR) as Recycled and Sustainable Filler in Styrene-Butadiene Rubber (SBR) Composites

Javier Araujo-Morera,Sergio González,Marianella Hernández Santana,Raquel Verdejo,Reyes Verdugo-Manzanares,Miguel Angel Lopez-Manchado

doi:10.3390/jcs5030068

Javier Araujo-Morera, Sergio González + Show 4 more

Open Access

https://doi.org/10.3390/jcs5030068

Copy DOI

Abstract

The management of end-of-life tires (ELTs) is one of the main environmental issues that society faces nowadays. Recycling of ELTs appears as one feasible option for tackling the problem, although their incorporation as ground tire rubber (GTR) in other rubber matrices is limited due to poor compatibility. In this research, we report a successful combination of a cryo-grinding process with a chemical treatment for modifying the surface of GTR. Various cryo-grinding protocols were studied until a particle size of 100–150 µm was achieved. Chemical treatments with different acids were also analyzed, resulting in the optimal modification with sulfuric acid (H2SO4). Modified GTR was added to a styrene-butadiene rubber (SBR) matrix. The incorporation of 10 phr of this filler resulted in a composite with improved mechanical performance, with increments of 115% and 761% in tensile strength and elongation at break, respectively. These results validate the use of a recycled material from tire waste as sustainable filler in rubber composites.

Highlights

The rational use of raw materials and polymer waste management, especially end-oflife tires (ELTs), is a global problem
We present a successful combination of a mechanical process and a chemical modification for the modification of the surface of ground tire rubber (GTR) that can achieve excellent mechanical properties in styrene-butadiene rubber (SBR)/GTR composites with only 10 phr of GTR
There does not seem to be a considerable difference between the three protocols, protocol P1 resulted in a narrower particle size distribution

Summary

Introduction

The rational use of raw materials and polymer waste management, especially end-oflife tires (ELTs), is a global problem. One possible solution to this disposal issue is to recycle the waste and reuse it. Recycling of resources and products is one of the main strategies of the circular economy (CE) model, providing an alternative to the traditional linear economy. The CE model aims to take care of the environment and achieve a sustainable society, keeping resources in use for as long as possible and reducing costs and waste [1]. It is possible to give a second lifecycle to a considerable number of used tires. The first stage in any tire recycling route should involve the consideration of the production of ground tire rubber (GTR), a fine granular material obtained from worn tires. Dry or wet ambient mechanical grinding and cryogenic grinding are some of the various methods used to obtain GTR [2,3]

Objectives

Methods

Results

Conclusion