Improving interface performance between the fibers and rubber using metal cations synergistic polydopamine to modify carbon fibers

CF‐PDA‐M hybrid fillers are prepared by three metal cations (M) assisting polydopamine (PDA) through Fe3+, Ni2+, and Al3+. The metal cations promote the polymerization of PDA on the fiber surface, shorten the modification time of the fibers, and ensure that the short‐cut carbon fibers (CF) do not agglomerate during water bath stirring while keeping the structure of the CF undamaged, which is a green and efficient method. After PDA modification, the roughness and surface activity of the fiber surface increase. Finally, CF‐PDA‐M is used as a filler and added to neoprene latex and natural latex, which are prepared into composites by wet blending, and the CF are characterized by different techniques. The results show that the hydroxyl and amino groups on the surface of CF‐PDA‐M increase the cross‐linking density of the composites, establish a good stress cross‐linking network, shorten the vulcanization time, effectively prevent the agglomeration phenomenon of the CF in the rubber, and improve the dispersion of the CF in the composite. After modification, the tensile strength and 300% constant tensile strength of CF‐PDA‐M increase by more than 10% and 30%, respectively, over CF composites, and the rolling resistance is reduced. This study provides a new and effective strategy for CF surface functionalization, which improves the processing efficiency and mechanical properties of rubber products and has a broad application prospect in the rubber industry.