Bispillar[5]arene-Based Slide-Ring Polyrotaxanation Enables Enhanced Toughness, Recyclability, Impact, and Puncture Resistance of Polyisoprene Elastomers.

A series of slide-ring polyrotaxanes (SRPs) have been constructed by the solvent-free blending of a ditopic pillar[5]arene () and polyisoprene (PIP) after thermal annealing. Solid-state C NMR experiments supported the fact that the pillar[5]arene rings of were threaded by PIP chains to afford physically interlocked networks. Tensile tests revealed that 1% of can improve the elongation at break from 50 to 239%, the tensile modulus from 2.1 to 3.9 MPa, and the toughness from 0.35 to 4.5 MJ/m. Impact and puncture resistance experiments show that the -doped materials exhibit remarkable enhancement of protective and impalement-resistant performance. The samples can be also recycled repeatedly due to their physical crosslinking nature. The important stress delocalization effects have been attributed to the pulley effect of in the SRP materials, which represents a supramolecular approach for improving the performance of PIP elastomers.