Combinations of natural rubber (NR), butadiene rubber (BR), and reclaim rubber (RR) were prepared with a view to producing low-cost re-treading materials. It was found that cure time and scorch time decreased with the increase in the reclaim content. Only a small reduction in the properties was observed in almost all systems upon the addition of 30 phr of reclaim rubber. Systems with good abrasion resistance and tensile strength were obtained. High tensile values of 22.8 and 20.1 MPa were able to obtain for the NR-rich system. Tear strength can be enhanced by the addition of reclaim rubber. Elongation at break was higher for all the systems even after adding 30 phr of RR. Modulus and compression set values were increased with RR loading. The thermal behavior and activation energy of NR/BR/RR blends were improved by the addition of RR. The phase morphology of the blends was studied using a scanning electron microscope.

Keywords: activation energy, natural rubber/butadiene rubber blend, reclaim rubber, thermogravimetric analysis, scanning electron microscope analysis.