The study of ionic and entanglements self‐healing behavior of zinc dimethacrylate enhanced natural rubber and natural rubber/butyl rubber composite

Abstract This study reported the self‐healing behavior of natural rubber (NR) and NR‐butyl rubber (IIR) composites, which was enhanced by graft‐polymerization of zinc dimethacrylate (ZDMA) onto rubber chains. Using dicumyl peroxide (DCP) as the vulcanization agent formed a reversible covalent/ionic crosslinking supermolecular network. By controlling the vulcanization process, a reversible supramolecular network composed of covalent cross‐linking, ionic cross‐linking, and physical entanglement is obtained. Experiments shown that the self‐repairing behavior of ionic bonds comes from the recombination of ionic clusters. Although the saturated backbone of IIR is hardly to provide ionic or covalent crosslinks, the addition of IIR can increase the degree of physical entanglements level of rubber and provide physical self‐healing behavior. The entanglement healing is weaker than ionic cross‐linking, but due to the better chain mobility, the multiple times healing ability of IIR introduced by entanglements is better than covalent or ionic bonds.