Advanced carbons in polymers

The polymers sector overlaps with plastics for thermoplastics but also covers the thermoset resins, including epoxies, polyurethanes and phenolics, that form the matrix of carbon fibre reinforced composites. In that role carbon fibre reinforces the polymer matrix rather than acting as an additive, while graphene and carbon nanotubes modify the matrix itself to improve fracture toughness, thermal stability and conductivity. Added to epoxy at under 5% by weight, nanotubes and graphene bridge nanoscale cracks and have been reported to improve mode-one fracture toughness by 20 to 40%, which matters for aerospace and wind-blade laminates.

In thermoplastic compounds, short carbon fibre provides macro-scale reinforcement while carbon nanotubes add conductivity at lower loading, and graphene nanoplatelets cut the gas permeability of polyurethane coatings by 50 to 80%. Biochar and biomass-derived carbons are compounded into bio-based polymers such as PLA and PBS as functional fillers that lower carbon footprint while improving stiffness. At the extreme, phenolic resin and carbon fibre are pyrolysed and graphitised above 2,000 degrees Celsius to form carbon-carbon composites for rocket nozzles and re-entry heat shields.

The polymer matrix nanocomposite market was valued at about $8.91 billion in 2023 and is forecast to grow at roughly 18.2% a year to 2032, with a graphene-driven view of the same market sized at about $10.49 billion and growing at around 16.6% annually. Carbon fibre reinforced thermoplastic is the fastest-growing carbon fibre application, helped by faster injection-moulding cycle times than thermoset processing. Multi-walled carbon nanotubes traded at about $50 to $300 per kilogram in 2025.