Effect of Thermal Aging on the Mechanical Properties of Rubber Composites Reinforced with Carbon Nanotubes

The incorporation of carbon nanotubes (CNTs) enhances the mechanical performance of rubber composites. This study examines the effect of single-walled CNTs (1-4 phr) on the properties of a natural rubber compound for sealing applications, both before and after thermal aging, as prolonged exposure to elevated temperatures can alter material properties, affecting durability and functionality. The researched nanocomposites were subjected to a series of mechanical tests, dynamic mechanical analysis, and surface investigation using atomic force microscopy (AFM). After adding 4 phr of CNTs, tensile and tear strength increased by 11.73% and 14.64%, respectively, while aging-related strength degradation was reduced by 5%. CNTs also increased complex modulus and hardness but reduced elongation at break and rebound resilience. Residual deformation in tensile and compressive set tests decreased. AFM analysis confirmed improved surface stability after thermal aging compared to the CNT-free compound.