“…The test conditions, such as the test sample shape and dimension, crosshead speed of the machine and testing temperature, follow either ASTM or ISO standards to minimize the occurrence of variations, while ASTM D412 is mostly employed to conduct tensile tests for an elastomer involving a dumbbellshaped specimen. In order to evaluate the healing performance of a self-healable rubber, the rubber sample is subjected to stretching until the break, and the fracture surfaces are joined together and sent for healing treatment and re-tested under the same testing conditions [104][105][106] Chen et al 107 studied the tensile properties of self-healing epoxidized natural rubber (ENR) after different healing conditions and the healing efficiencies of the rubber compound with different dithiol-bearing boronic ester (BDB) content, as shown in Figure 21. In this work, BDB was used as a crosslinker to create a rearrangeable crosslink network based on the reaction between thiols and epoxy groups, contributing to the self-healing ability of ENR.…”