Electron‐Beam Irradiation of Ground Tire Rubber in Water for Surface Activation and Improved Recycling in Natural Rubber Compounds

ABSTRACT

In this study, we treated ground tire rubber (GTR) with electron‐beam irradiation in an aqueous medium and investigated its application in natural rubber (NR)‐based compounds. We characterized the changes in the internal chemical structure using Soxhlet extraction and swelling tests. Based on the results, it can be stated that both the sol content and the crosslink density changed only slightly (1%–2%), indicating that the energy imparted during electron irradiation was primarily consumed by the radiolysis of water. We used the irradiated GTR in NR‐based compounds and then examined their properties. The tensile strength of the vulcanizates increased by 30%, while their elongation at break increased by 28% compared to the reference, even at an absorbed dose of 10 kGy. The tear strength reached its maximum at 40 kGy, where it increased by 42% compared to the reference. Based on the dynamic mechanical properties, it can be concluded that radiation treatment resulted in stronger adhesion between the phases, as evidenced by a decrease in the Payne effect. The results demonstrate that the water‐radiolysis‐assisted surface activation concept previously developed using gamma irradiation can be successfully transferred to electron‐beam processing, providing a faster and more economically attractive route for industrial GTR recycling.