Healable, Recyclable, and Scratch-Resistant Polyurethane Elastomers Cross-Linked with Multiple Hydrogen Bonds
Tiantian Yang, Xingyuan Lu, Xiaohan Wang, Yixuan Li, Xiangjin Wei, Wenjie Wang, Junqi Sun
Abstract
Despite the rapid development of elastomers as safeguard materials, efforts remain to be made to further improve their comprehensive mechanical properties and endow them with healing and recycling capacities. Herein, mechanically robust, healable, recyclable, and scratch-resistant polyurethane (PU) elastomers are successfully fabricated by dynamically cross-linking PU chains with multiple hydrogen bonds, which are derived from the carbamate, carboxylic acid, and 2-ureido-4-[1 H ]-pyrimidinone (UPy) groups. The resultant elastomers (denoted as PU-UPy-DPA) are highly elastic and exhibit a high tensile strength of ∼73.6 MPa and toughness of ∼257.2 MJ m –3 . The excellent comprehensive mechanical properties endow the PU-UPy-DPA elastomers with excellent scratch-resistant and tear-tolerant capacities to improve their long-term durability. Owing to the reversibility of hydrogen bonds among the PU chains, the PU-UPy-DPA elastomers can be conveniently healed and recycled under heating to restore their original mechanical properties. Additionally, the PU-UPy-DPA elastomers can be homogeneously loaded with organic dyes and luminescent nanoparticles to gain desired colors and luminescence, which helps to extend their application ranges.