Improving Dispersion and Mechanical Properties of Natural Rubber and Ethylene Propylene Diene Monomer Composites With Ionic Liquid‐Modified Helical Carbon Nanofiber

ABSTRACT This study presents an innovative “ionic liquid (IL) modification‐spray compounding” technique to enhance the dispersibility of helical carbon nanofiber (HCNF) and fabricate IL‐modified HCNF/silica composite fillers. These fillers were used to reinforce natural rubber/ethylene‐propylene‐diene monomer (NR/EPDM) composites. Results show that the composite filler modified with 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([C ₄ MIM]BF ₄ ) achieved the most uniform dispersion in the rubber matrix. Compared with the pure silica sample, the composite material exhibited improvements in shore hardness, stress at 300% strain, tensile strength at break, tear strength, rebound resilience, and abrasion resistance by 6.46%, 24.43%, 12.02%, 6.94%, 12.01%, and 22.75%, respectively. IL played a crucial role in the surface modification of HCNF, enabling their excellent dispersion and full reinforcement efficiency within the matrix. This research provides a novel and industrially promising strategy to address the dispersion issues of HCNF and improve the comprehensive properties of composite materials, opening up new avenues for the development of related materials.