Devulcanization of Scrap Ground Tire Rubber and Successive Carbon Nanotube Growth by Microwave Irradiation

Short-term microwave irradiation was effectively used to devulcanize scrap ground tire rubber (GTR) particles. Microwave devulcanization was a short-time procedure, i.e. 1 min, 2 min and 4 min, during which, the GTR particles were exposed to continuous irradiation in order to cleave the cross-linked mono/di/poly sulfidic bonds (S-S, C-S) among their molecules to obtain the natural rubberlike ingredient. After that, polypyrrole (PPy) coated devulcanized GTR particles (PPy/dGTR) were used as substrates to grow carbon nanotubes (CNTs) on their surfaces through another rapid microwave treatment. Here, PPy coating had served as the effective microwave absorbing layer and the organic metallocene precursor (ferrocene) was used as the nucleation agent to promote the CNT growth. Eventually, the as-obtained products from each step were characterized in details via TGA, DSC, FT-IR, SEM, TEM, and their corresponding results were reported in order to verify and prove the success of the above mentioned methodology.