Synthesis of urethane-modified aliphatic epoxy using a greenhouse gas for epoxy composites with tunable properties: Toughened polymer, elastomer, and pressure-sensitive adhesive

Abstract Epoxy, which exhibits tunable mechanical properties, has been investigated to overcome its inherent brittleness and extend its application range. Herein, various epoxy composites, including a toughened polymer, elastomer, and pressure-sensitive adhesive (PSA), with tunable mechanical properties were prepared by adjusting the ratio of a rigid aromatic epoxy and flexible aliphatic epoxy. A flexible aliphatic epoxy that incorporated urethane linkages was used to extend the tuning range; it was synthesized via an eco-friendly route utilizing CO2 without isocyanate. The prepared toughened polymer-like and elastomeric epoxy composites can be used in structural epoxy adhesive (lap shear strength = 27.8 MPa) and flexible electronics (plastic strain PSA . This work proposes a new application of eco-friendly epoxies and a strategy to facilitate the wide tuning range of epoxy materials, including PSAs.