Processing, physico-mechanical and thermal properties of reclaimed GTR and NBR/reclaimed GTR blends as function of various additives

In this work, ground tire rubber (GTR) was mechano-chemically reclaimed in the presence of bitumen and various additives. During studies three types of processing and curing additives: (i) peptizer P300; (ii) vulcanization accelerator tetramethylthiuram disulfide (TMTD) and (iii) organic peroxide di(2-tert-butyl-peroxyisopropyl)benzene (BIB1) were applied to enhance reclaiming of GTR. Reclaiming process was evaluated by oscillating disc rheometer measurements, followed by physico-mechanical and thermal properties analyses performed on vulcanized reclaimed rubber. Additionally, the impact of used additive type on the selected properties of NBR/reclaimed GTR blends were also evaluated. The results showed that application of peptizer P300 and TMTD accelerator improves processing of obtained reclaimed rubber, while simultaneously the mechanical properties of reclaimed rubber decreased as function of additive type, in the order: peptizer P300 > peroxide BIB1 > accelerator TMTD. On the other hand, this tendency was less visible in case of NBR/reclaimed GTR blends. This phenomenon is related to cross-linking efficiency of used additives which was confirmed by swelling behavior, FTIR and TGA-FTIR analysis. Presented investigations confirmed that application of processing and curing additives during mechano-chemical reclaiming is interesting route to modify the final properties of reclaimed rubber and its blends with the fresh rubber compounds.