A Novel Self-Healing Polyurethane Based on Disulfide Bonds

Polymeric materials with intrinsic self‐healing ability that can restore from mechanical injury autonomously have attracted great research efforts recently. Disulfide bonds, which become dynamic upon exposure to heat, UV light, or redox conditions, can be used to introduce healable properties to polymer network. Shape memory effect is a kind of auxiliary recovery force that can accelerate healing process. In this work, a polyurethane material combines disulfide link and shape memory effect is synthesized. Autonomous healing of a crack takes place upon heating above 80 °C and leads to almost fully recovery of mechanical properties. This healing is achieved by activating shape memory effect and disulfide exchange reaction simultaneously. A self‐healing polyurethane based on the combination of disulfide bond and shape memory effect is synthesized. The resulting polyurethane can initiate self‐healing by heating to 80 °C and the scratches on sample almost disappear within 5 min. A healing process of 4 h can achieve recovery of approximately 92 and 100% of the original tensile strength and elongation at break, respectively.