Study of mechanical and chemical properties stability of inner tubes exposed to gamma radiation

Abstract

Nowadays, car tires are not provided with inner air or tubeless, pointing toward a technical evolution. Nevertheless, trucks tires even use at present inner tires, composed almost fully by a synthetic material, which ensures either a good potential for air constraint or longer periods for inspection of tires pressure. Inner tire is located inside the tire, which does not have any extra sealing in the wheel to withstand compressed air. It is designed to resist to expansion of these elements, inside common tires. This rubbery and vulcanized coating has chemical and physical characteristics which enable it to bear a very high air pressurization, avoiding leakages while protects tire outer frame. Inner tires models are exposed to higher temperatures and pressures that contribute to accelerate abrasion. This work aims to the study of mechanical properties changes of an inner tire used in trucks, after gamma rays exposure, in order to promote further material recycling. Ionizing radiation choice was due to its capacity to modify materials structure and properties besides its applicability for rubbers recycling/recovery. For samples characterization, non-irradiated and irradiated at 5, 10, 15, 20, 25 and 30 kGy, there were accomplished following tests: tensile and elongation at break, hardness, and thermal ageing and CHN elementary analysis. It was observed a decrease in mechanical properties for irradiated samples at doses higher than 20 kGy.