Development of bus body rubber profiles with additives from renewable sources: Part II – Chemical, physical–mechanical and aging characterization of elastomeric compositions

The aim of this work was to characterize the chemical, physical–mechanical and aging properties of elastomeric compositions containing additives from renewable sources designed to replace the components traditionally used at rubber industry. The elastomeric compositions were processed in a torque rheometer with an acceleration system added into a laboratory two-roll mill. The compositions were prepared using varying proportions of a vulcanization activator – MDECR®, vegetable oil – MD600® and a loading filler – MDCO®. The resulting materials were characterized in terms of their cross-link density and physical–mechanical properties, including Shore A hardness, tensile strength and tear strength. The samples were also subjected to accelerated thermo-oxidation aging. The best physical–mechanical performance was achieved with a composition of 4 parts per hundred of rubber (phr) MDECR® and 10 phr MD600®, promoting a 75% reduction in the zinc content and a 60% reduction in the oil content. The cross-link density and physical–mechanical properties were not affected by MDCO®, which was used as a filler to reduce the costs of the material. The cross-link density decreased in materials containing MDECR® and MD600®. Satisfactory aging resistance was observed for compositions containing MD600® and MDCO®.