Robust Vanillin-Derived Poly(thioether imidazoles) as Both a Latent Curing and Toughening Agent for One-Component...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• One-component epoxy resins require latent curing agents for stability and processability.
• Developing sustainable latent curing agents is crucial for advancing epoxy resin technology.

Purpose of the Study:

• To design and synthesize a biobased polymerizable imidazole monomer from lignin-derived vanillin.
• To prepare robust poly(thioether imidazoles) via thiol-ene polymerization.
• To evaluate the potential of these poly(thioether imidazoles) as latent curing and toughening agents for epoxy resins.

Main Methods:

• Lignin-derived vanillin was used to synthesize a biobased imidazole monomer with diene functionality.
• Thiol-ene polymerization was employed to create poly(thioether imidazoles).
• The synthesized poly(thioether imidazoles) were blended with commercial epoxy resins and their curing behavior and stability were assessed.

Main Results:

• A novel biobased imidazole monomer was successfully prepared from lignin-derived vanillin.
• A series of poly(thioether imidazoles) with tunable structures and properties were synthesized.
• The poly(thioether imidazole) precursors exhibited excellent storage stability, remaining fluid at 25 °C for over 90 days.
• Rapid curing into robust resins was achieved upon heating.

Conclusions:

• The synthesized poly(thioether imidazole) functions effectively as both a latent curing and toughening agent for one-component epoxy resins.
• The imidazole groups facilitate homopolymerization, while the aliphatic chain enhances toughening.
• This approach offers a sustainable alternative for developing high-performance epoxy resin systems.