Constructing Tannic Acid‐Iron Ion Metal Skeleton Layer on Polyester Fibers for Strengthening Rubber Composites Interface

ABSTRACT In the paper, by complexing tannic acid (TA)‐iron ions (Fe ³⁺ ) to form a metal network skeleton structure and introducing glycerol triglycidyl ether (GTE) into the above metal network skeleton to modify the polyethylene terephthalate (PET) fibers, the bonding strength between fibers and rubber is enhanced further. Accordingly, the peeling performance between fibers and rubber is improved largely because of active groups (such as phenolic hydroxyl and epoxy groups). The surface morphologies, compositions, structures, thermal stability, and mechanical properties of the modified PET fibers were analyzed by SEM, FTIR, AFM, and TG. The results show that the optimal treatment process is the molar ratio 1:3 of TA to Fe ³⁺ , the solution pH 8.62, the fiber soaking treatment time 6 h, and 0.52 g/mL of GTE. Thus, a continuous TA‐Fe ³⁺ metal network skeleton structure layer is formed on the fiber surface, and the treatment did not damage the strength and thermal stability of the PET fibers. Last, the peel strength is increased 48% with introducing GTE compared with PET‐RFL/rubber composites. This treatment is simple to operate and has a low cost, which is expected to be applied in the future.