Enhanced adhesion property of aramid fibers by polyphenol-metal iron complexation and silane grafting

In this work, a green and efficient method for the surface modification of aramid fibers is proposed, aiming to enhance their adhesion property with rubber matrix. The surface of the aramid fibers was pre-deposited with a polyphenol-metal complex coating via rapid (1 min) complexation between FeIII ions and tannic acid (TA), followed by silane grafting. The influences of reactant concentration and reaction temperature on the grafting efficiency of bis-(γ-triethoxysilylpropyl)-tetrasulfide (Si69) were also characterized. The adhesion force of the modified aramid fibers/rubber composites showed a maximum improvement of 73.6% compared to that of untreated aramid fibers/rubber composites. This approach showed great potential in rubber industry due to its low-cost and high-efficiency.