Mechanoresponsive ionic elastomers with Ultra-Stretchability, high toughness, fatigue resistance, and extreme temperature resistance

In the development of elastic materials, the non-synergy between stretchability and toughness is a challenge. Herein, we propose a rational design of a composite hydrogel by introducing strongly polarized hydrated Li-ion clusters, electron-withdrawing carboxyl groups, and Sn(II) complexation into hydrogen-bonded poly(acryl-amide) (PAM) network. Weak interaction between Li-ions and amide groups facilitates the rapid flipping and slipping of the PAM chains during stretching, optimizing the stretchability of the hydrogel. This composite also provides an energy-dispersing mechanism based on strong ionic complexation between Sn(II) and amide groups, which improves its toughness. As-prepared composite hydrogel simultaneously exhibits high stretchability (>7000% elongation), ultra toughness of 580 kPa, excellent fatigue resistance and extreme temperature resis-tance (elastic at -60 and 70 degrees C). Due to its excellent comprehensive performances, the present soft material has broad application prospects in agriculture, medicine, construction, and machinery.