Bio-Based Epoxy Vitrimer

Heat-Triggered Scratch Repair

A lignin-derived epoxy vitrimer that rapidly heals scratches via transesterification at elevated temperatures, while cured resins maintain mechanical strength comparable to petroleum-based epoxies and enable recyclability of carbon fiber composites.

Lin, Haidan · Kai, Dong · Zhao, Di · Zhao, Chengji · Li, Xuefeng

Polymers 2025

Specifications

Scratch repair rate

{'zh': '90', 'en': '90'} %

Tensile strength (resin)

{'zh': '69', 'en': '69'} MPa

Flexural strength (resin)

{'zh': '105', 'en': '105'} MPa

Tensile strength (CFRP)

{'zh': '543', 'en': '543'} MPa

Flexural strength (CFRP)

{'zh': '414', 'en': '414'} MPa

Advantages

Scratches heal with heat

Dynamic transesterification networks rearrange at elevated temperature, repairing ~90% of surface scratches in 30 min.

Carbon fiber is recyclable

The CFRP degrades in ethylene glycol solvent, and recovered carbon fibers preserve surface morphology and chemical structure.

Bio-based alternative to BPA

The epoxy monomer is synthesized from a lignin derivative, avoiding petroleum-derived bisphenol A.

Strength on par with petroleum CFRP

Bio-based CFRP shows tensile strength of 543 MPa and flexural strength of 414 MPa, comparable to commercially available petroleum-derived CFRP.

Applications

• Carbon Fiber Recycling：CFRP degrades in ethylene glycol, enabling non-destructive recovery of carbon fibers.
• Self-Healing Coatings：Coatings repair ~90% of scratches at 220 °C in 30 min.
• Bio-Based Epoxy：Uses a lignin derivative to replace bisphenol A in epoxy resin.
• Aerospace Composite Maintenance：Damage in composites can be thermally repaired, extending service life.
• Structural Repair in Construction：Surface scratches in structures self-heal upon heating, avoiding part replacement.