Effect of Zn2+ salt bonding on thermo‐reversible self‐healing natural rubber

A series of intrinsic self‐healing natural rubber (NR) integrated with thermo‐reversible (zinc) Zn2+ salt bonding networks was successfully fabricated via reversible ionic interaction approach. The formation of Zn2+ salt bonding in the rubber networks was evidenced by FTIR analysis. The developed materials showed excellent self‐healing capability as the properties could recover up to 76% under tensile mode and 100% under tear mode and fatigue. The crosslink density of self‐healing NR‐g‐MAA/ZT rubber obtained from the swelling test evident that interaction between NR‐g‐MAA and zinc thiolate (ZT) increased with the self‐healing ability of the materials. SEM images suggested the occurrence of chain diffusion between the fracture interfaces when the broken pieces were brought in contact with each other's. The reconnection of ionic salt bonding is expected to allow rearrangements of rubber segments, which turns NR‐g‐MAA into potential self‐healing rubber materials.