Lignin-derivable non-isocyanate polyurethane-epoxy hybrid thermosets with tunable thermal properties


  • Jessica Williams, Chemistry, Johns Hopkins University

Faculty Mentor(s)

  • Thomas Epps, Chemical Engineering, University of Delaware
  • LaShonda Korley, Materials Science & Engineering, University of Delaware


Lignin-derivable precursors have potential as safe, bio-based alternatives to toxic, petroleum-based building blocks in polyurethanes and epoxies. In this study, motivated by the structural similarity between petroleum-derived bisphenols and bio-derivable bisguaiacols, we explored the utility of these monomers in non-isocyanate polyurethane (NIPU) – epoxy hybrid networks. These hybrid networks are diglycidyl ethers cured with amine-terminated linear NIPUs, wherein the high strength of epoxy-amine systems and flexibility of the thermoplastic NIPU backbone could be utilized to enhance the thermomechanical properties of the resulting thermosets. Bisphenol A diglycidyl ether (BADGE) was cured with NIPU-amine crosslinkers prepared by reacting bisphenol A cyclic carbonate with excess bifunctional amines of varied chain lengths. The variation in amine chain length provided tunability of network architecture and allowed the formation of NIPU-epoxy hybrids with a broad range of glass transition temperatures making them suitable for both flexible and rigid applications. Additionally, the ratio of NIPU-amine crosslinker and epoxy was varied to study its effect on the thermal properties and curing kinetics of NIPU-epoxy hybrid thermosets. Overall, the fundamentals related to the formation of NIPU-epoxy hybrid networks established in this work provide a promising framework for the design of sustainable NIPU-epoxy hybrid thermosets based on bio-derivable precursors.