RECLAIMING OF GROUND RUBBER TIRE BY SAFE MULTIFUNCTIONAL RUBBER ADDITIVES: II VIRGIN NATURAL RUBBER/RECLAIMED GROUND RUBBER TIRE VULCANIZATES

Mechanochemically reclaimed ground rubber tire (GRT) was revulcanized in combination with virgin natural rubber (NR). The NR/GRT vulcanizates with GRT content 20-50 wt% were prepared and studied. Reclaiming of GRT was successfully carried out by tetra benzyl thiuram disulfide (TBzTD) in the presence of spindle oil at around ambient temperature. The cure characteristics and mechanical properties of the virgin NR/reclaimed GRT blend were studied. Increasing the reclaimed rubber (RR) content in the blend decreases the optimum cure time without altering the scorch time. The effect of carbon black was studied in NR/RR (80/20) blend vulcanizate for the ultimate use of NR/RR blend vulcanizate. Aging characteristics of different NR/RR blends were evaluated. The swelling behavior, thermo-gravimetric analysis, and dynamic mechanical properties of NR/RR blend vulcanizates were examined. The equilibrium swelling of the NR vulcanizates was reduced with increasing reclaimed rubber content. Thermal stability of the blend vulcanizates was increased with increase in reclaimed rubber content. The elastic and storage modulus of the NR/RR vulcanizates improved with increasing reclaimed rubber content. Scanning electron microscopy studies further indicate the coherency and homogeneity in the NR/RR vulcanizate.