Superstretchable, Self‐Healing Polymeric Elastomers with Tunable Properties

Utilization of self‐healing chemistry to develop synthetic polymer materials that can heal themselves with restored mechanical performance and functionality is of great interest. Self‐healable polymer elastomers with tunable mechanical properties are especially attractive for a variety of applications. Herein, a series of urea functionalized poly(dimethyl siloxane)‐based elastomers (U‐PDMS‐Es) are reported with extremely high stretchability, self‐healing mechanical properties, and recoverable gas‐separation performance. Tailoring the molecular weights of poly(dimethyl siloxane) or weight ratio of elastic cross‐linker offers tunable mechanical properties of the obtained U‐PDMS‐Es, such as ultimate elongation (from 984% to 5600%), Young's modulus, ultimate tensile strength, toughness, and elastic recovery. The U‐PDMS‐Es can serve as excellent acoustic and vibration damping materials over a broad range of temperature (over 100 °C). The strain‐dependent elastic recovery behavior of U‐PDMS‐Es is also studied. After mechanical damage, the U‐PDMS‐Es can be healed in 120 min at ambient temperature or in 20 min at 40 °C with completely restored mechanical performance. The U‐PDMS‐Es are also demonstrated to exhibit recoverable gas‐separation functionality with retained permeability/selectivity after being damaged. Urea‐functionalized poly(dimethyl siloxane)‐based elastomers with extremely high stretchability, self‐healing mechanical properties, and recoverable gas‐separation performance are fabricated. Tailoring the molecular weights of poly(dimethyl siloxane) offers tunable mechanical properties, such as ultimate elongation (from 984% to 5600%), Young's modulus, toughness, and elastic recovery. After mechanical damage, the elastomers can be healed in 2 h at ambient temperature with completely restored mechanical properties and recovered gas‐separation functionalities.