Grafting and reactive extrusion technologies for compatibilization of ground tyre rubber composites: Compounding, properties, and applications

Chemical modification of ground tyre rubber (GTR) to compatibilize it with the matrix is a well-known approach. Based on our recent review of the surface etching methods used in GTR modification, the purpose of the current work is to take a deeper look into more advanced methods such as grafting and reactive extrusion. While grafting is more efficient in achieving compatibility, however, it usually involves multi-step synthesis protocol and purification procedures making it very difficult to be applied in the industry. On the other hand, reactive extrusion is easy to apply in the industry as it uses the same equipment that is already employed in the rubber and thermoplastics industries. Furthermore, it is solvent-free and achieves compatibility via in-situ grafting of GTR and the matrix. The composites properties achieved via each of these processes and the resulting properties are highlighted in this work. For grafting, the initiation methods used to introduce an active centre onto the GTR are also highlighted. [Display omitted]