The NR/CNT caused variations in the change in resistance (ΔR/R0) in different cycles, which implied the low recoverability of the conductive network. The behavior was affected by the conducting pathways of CNT, which were permanently damaged during multiple loading cycles (Natarajan et al., 2017). This finding can be well explained by the proposed model in Fig. 18, in which the CNT network, which acted as a conductive network in the NR matrix [Fig. 18(a)], was destroyed during the loading of 100% strain, as indicated by the red arrow in Fig. 18(b). However, after releasing the strain (strain unloading), the CNT network cannot recover [Fig. 18(c)], resulting in the permanent break down of the conductive network, which led to the unstable ΔR/R0 of the NR/CNT composite. Accordingly, the NR composite filled with CNT–CNF1:0.05 also presented the instability of ΔR/R0. This result indicated that the CNT network with the fine dispersion of CNT, as evidenced by the particle analyzer result in Fig. 5, can be permanently damaged under multiple stretching cycles. However, an unexpected effect was obtained from the NR nanocomposites filled with