Moisture-resistant and room-temperature self-healing glassy plastic with thiocarbonyl and hyperbranched structure

Abstract

While glassy plastics capable of self-healing at room temperature have been developed, their reliance on polar supramolecular interactions makes them vulnerable to water vapor. In humid environments, these materials absorb moisture and become plasticized, resulting in decreased mechanical strength and thermal stability. In this study, we report a moisture-resistant glassy plastic (MRGP). This material features a high-density hydrogen bond network and long hydrophobic aliphatic chains with polar yet water-resistant thiocarbonyl groups, endowing it with both a high storage modulus of 2.0 GPa and remarkable hydrophobicity with a water contact angle of over 90°. Despite these properties, MRGP can self-heal at room temperature, which is attributed to the secondary relaxations of its branched chains that can drive the reorganization of the terminal thiocarbamate groups. Moreover, ethanol can trigger instantaneous healing of MRGP by activating its thiocarbonyl groups on the fractured surface. Additionally, MRGP is found to exhibit linear dielectric properties, and thus it has great potential in advanced functional and structural industries.