To Clarify the Resilience of PEBA/MWCNT Foams via Revealing the Effect of the Nanoparticle and the Cellular Structure

The objective of this study is to clarify the resilience of the poly(ether-mb-amide)/multiwalled carbon nanotube (PEBA/MWCNT) composite foams from the perspectives of the nanoparticle and the cellular structure. The PEBA/MWCNT composites were prepared via a solution blending process with different contents of MWCNTs (0, 0.1, 1, and 5 wt %), and then the PEBA/MWCNT foams were prepared via a subsequent two-step batch foaming technique. The cyclic tensile test was performed with a universal testing machine, and the inelastic behavior of the composites and the foams was estimated based on the cyclic strain–stress curves. It was found that the incorporation of the MWCNT not only enhances the inelastic behavior of the composites via increasing the modulus but also brings in improved resilience of the foams compared to the composites via decreasing the cell size and increasing the cell density. The foam with 0.1 wt % content of MWCNT exhibits the best resilience. It is considered that the competition between the two effects of the nanoparticles of restricting chain mobility and altering the cellular structure might be the reason to bring the best resilience at a suitable content of the nanoparticles. The resilience of the foams with different contents of MWCNT showed no significant dependence on the expansion ratio and the modulus, which allows for their potential applications in the fields of high-end sport shoes and sports apparatus.