Low‐Temperature Resistant and Biocompatible Hot‐Melt Adhesives Enabled by Triblock Thermoplastic Polyester Elastomers

ABSTRACT

The state‐of‐art commercial polymeric adhesives are mainly petroleum‐based, non‐biodegradable and not tolerant of low temperature, severely limiting their applications in extremely cold regions. Current research efforts focus on development of sustainable and biodegradable polyester‐based adhesives. However, nearly all the reported polyester‐based adhesives were used at room temperature, and the innovative functional polyester‐based adhesives with low‐temperature‐resistance are very rare. Herein, we rationally designed and synthesized triblock thermoplastic polyester elastomers, poly(1,4‐dioxan‐2‐one)‐ b ‐poly( γ ‐methyl‐ ε ‐caprolactone)‐ b ‐poly(1,4‐dioxan‐2‐one) (PPDO‐ b ‐PMCL‐ b ‐PPDO), serving as high‐performance biodegradable hot‐melt adhesive with excellent low‐temperature‐resistance. The mechanical and viscoelastic properties of polyester‐based adhesives could be readily modulated by varying molecular weight and fraction of hard/soft blocks via controlled ring‐opening polymerization. PPDO‐ b ‐PMCL‐ b ‐PPDO with appropriate volume fraction of hard blocks exhibited strong adhesion to a range of substrates (with a bonding strength high up to 5.0 MPa) both at room temperature and even at cryogenic temperature (−196°C). The polyester elastomer‐based adhesives outperformed some common commercial petroleum‐based hot‐melt adhesives, showing their great potential in the specific scenarios like polar‐region exploration.