Poly(methyl methacrylate) as Healing Agent for Carbon Fibre Reinforced Epoxy Composites

Area of Science:

• Materials Science
• Composite Materials
• Polymer Science

Background:

• Damage to fibre-reinforced plastics (FRPs) necessitates costly and time-consuming repairs.
• Self-healing materials offer a promising solution for in-service repair of composites.
• Poly(methyl methacrylate) (PMMA) has not been previously investigated as a self-healing agent in FRPs.

Purpose of the Study:

• To investigate the efficacy of poly(methyl methacrylate) (PMMA) as a self-healing agent in fibre-reinforced plastics (FRPs).
• To evaluate PMMA's performance when blended with the matrix versus when used as a carbon fibre coating.
• To assess the long-term healing capacity over multiple cycles and the impact of a transesterification catalyst.

Main Methods:

• Incorporation of PMMA into FRPs via matrix blending and carbon fibre spray coating.
• Evaluation of self-healing properties using double cantilever beam (DCB) tests.
• Assessment of fracture toughness recovery over three healing cycles.
• Comparison of healing efficiency with and without a transesterification catalyst.

Main Results:

• Matrix blending of PMMA did not result in self-healing due to its morphology.
• Coating carbon fibres with PMMA yielded healing efficiencies up to 53% in fracture toughness recovery.
• Healing efficiency remained consistent over three cycles.
• A transesterification catalyst did not enhance healing but improved interlaminar properties.

Conclusions:

• Spray coating PMMA onto carbon fibres is a scalable and effective method for achieving self-healing in FRPs.
• PMMA-based self-healing demonstrates significant potential for cost-effective composite repair.
• The study provides valuable insights into optimizing self-healing strategies for composite materials.