Organically Modified Layered Double Hydroxide for Enhancing Aging Resistance of Styrene–Butadiene Rubber

As styrene–butadiene rubber (SBR) is widely used and tends to age, the performance improvement in aging resistance is greatly important to rubber industrial fields. To this end, this study considered using layered double hydroxides (LDHs) as inorganic fillers and subsequently modified them by silane coupling agent KH−580 to obtain organically functionalized LDHs (m−LDHs) for solving the compatibility and aging concerns. The modified fillers were incorporated into styrene–butadiene rubber (SBR) to prepare m−LDHs/SBR composites. To evaluate their aging resistance, both SBR and m−LDHs/SBR samples were subjected to ultraviolet (UV) accelerated aging tests. Comprehensive characterizations were carried out using Fourier−transform infrared spectroscopy (FT−IR), thermogravimetric analysis (TGA), and standard mechanical property testing. FT−IR confirmed the successful grafting of KH−580 onto LDHs surfaces, while TGA demonstrated a ~50 °C increase in decomposition temperature of the modified SBR compared to the pristine sample, indicating enhanced thermal stability. Mechanical performance, including tensile strength, elongation at break, and hardness, was better retained in m−LDHs/SBR after aging, revealing the role of m−LDHs as both UV shielding and interfacial reinforcing agents. These findings highlight the potential of surface−functionalized LDHs as multifunctional fillers to enhance the durability and service lifetime of rubber materials.