A self-reinforcing and self-healing elastomer with high strength, unprecedented toughness and room-temperature reparability

Abstract

It is still a formidable challenge to develop intrinsic self-healing elastomers with simultaneous high mechanical strength, toughness and room-temperature reparability. Herein, we report a mechano-responsive strategy, named as strain induced...

Healable and Recyclable Elastomers with Record‐High Mechanical Robustness, Unprecedented Crack Tolerance, and Superhigh Elastic Restorability

“…The two diffraction spots observed in the 2D WAXD patterns correspond to the deconvoluted Peak 1 and Peak 2 in the 1D WAXD profiles, centered at the scattering vector q of 14.3 and 16.8 nm −1 , which are assigned to the (020) and (110) planes of the crystalline methylene groups, respectively, of the PTMEG soft segments. [ 21,52 ] Furthermore, when the stretched samples were completely released, both the 2D WAXD patterns and the 1D WAXD profiles recover to the original states corresponding to the amorphous structures of the samples. All these results suggest that the soft PTMEG segments of both the IPDI‐SPU 2000 and TDI‐SPU 2000 elastomers undergo reversible strain‐induced alignment and crystallization, which play a significant role in strengthening the elastomers.…”

“…To the best of our knowledge, the healable and recyclable IPDI‐SPU 2000 elastomer exhibits both the highest‐ever tensile strength and the highest‐ever toughness among all the healable polymeric elastomers reported to date (Figure 3b). [ 17,20,21,27,28,40–52 ] The stress–strain behaviors of the IPDI‐SPU 2000 and TDI‐SPU 2000 elastomers, measured at different strain rates, are shown and discussed in Figure S11, Supporting Information.…”

“…All these results suggest that the soft PTMEG segments of both the IPDI‐SPU 2000 and TDI‐SPU 2000 elastomers undergo reversible strain‐induced alignment and crystallization, which play a significant role in strengthening the elastomers. [ 21,52 ] The IPDI‐SPU 2000 and TDI‐SPU 2000 samples, stretched to different strains up to 800%, were also measured by FTIR spectroscopy. The results indicate that the fractions of the H‐bonded CO groups in both samples keep almost constant with the increase of strain (Figure S13, Supporting Information), suggesting that the H‐bonds between the hard segments of the elastomers can be dynamically reformed after strain‐induced rupture.…”

“…Remarkably, the fracture energy of the IPDI‐SPU 2000 elastomer (215.2 kJ m −2 ) represents a new world record for polymeric elastomers, including the healable and unhealable ones (Figure 4d). [ 2,6,15–21,50 ] Trouser tear tests were also performed to measure the fracture energy of the elastomers (Figure S15, Supporting Information). [ 22 ] The as‐measured fracture energy is 206.6 kJ m −2 and 103.2 kJ m −2 , respectively, for the IPDI‐SPU 2000 and TDI‐SPU 2000 elastomers, which are quite similar to the values measured by the Greensmith method.…”

“…[ 4–14 ] Moreover, robust elastomers with high crack tolerance can prevent the crack propagation, even if crack or cut exists, to significantly enhance their reliability and durability. [ 6,15–22 ] Unfortunately, it is a formidable challenge to develop healable and recyclable elastomers that possess high levels of contradictory mechanical properties and excellent crack tolerance. Employment of non‐covalent interactions as reversible crosslinks and sacrificial bonds is the most effective strategy to fabricate highly extensible, healable, and recyclable elastomers.…”