The impact of imidazolium ionic liquid-modified carbon nanotubes on the swelling resistance and mechanical properties of ethylene-propylene diene monomer/acrylonitrile butadiene rubber (EPDM/NBR) nanocomposites

Establishing strong interfacial interactions between fillers and the polymer matrix is crucial for producing high-performance polymer nanocomposites. This study explores the development of ethylene-propylene diene monomer/acrylonitrile butadiene rubber (EPDM/NBR) nanocomposites using multiwalled carbon nanotubes (CNTs) modified with imidazolium-type ionic liquids (IL-CNTs). The mole percent uptake (MPU) of various solvents by EPDM/NBR nanocomposite membranes was examined to assess filler-polymer interactions. Cure properties were analysed using a moving die rheometer. Mechanical performance was evaluated through tensile, tear and hardness tests. Swelling resistance, compression set and crosslinking density were assessed to determine the impact of IL-CNT incorporation on the nanocomposite properties. Results showed that increasing CNT content led to higher torque and shorter cure times. The tensile strength and stress at 100% elongation of CNT- and IL-CNT-filled EPDM/NBR nanocomposites improved with increasing nanofiller content up to 5 phr, after which they began to decrease. The tensile strength and stress at 100% elongation for IL-CNT-filled composites saw improvements of 155% and 70%, respectively, compared to the base vulcanisates. Other properties, including tear strength, hardness, abrasion resistance, swelling resistance, compression set and crosslinking density, also increased with higher nanofiller content in IL-CNT-filled EPDM/NBR composites.