Market and product

A review study by Malathi Sampath and colleagues, published in RSC Sustainability, shows a range of promising material solutions helping the tyre industry reduce its dependence on petroleum-based inputs — from bio-based rubbers and fillers to recycling technologies for rubber, steel, and carbon black.

The global tyre industry faces two parallel pressures: nearly 1.7 billion tonnes of waste tyres are generated every year, while some 4 billion used tyres remain stockpiled in landfills worldwide, a situation described as "black pollution." Improperly disposed tyres can release chemicals into the environment, emit methane and toxic smoke when burned, and become breeding grounds for disease-carrying mosquitoes.

In terms of materials, a tyre is a composite structure made of natural rubber, petroleum-based synthetic rubber, carbon black, textile reinforcement, and various additives. Raw materials account for as much as 65% of production costs, natural rubber supply currently lags behind demand, and most other components remain oil-dependent. The market for sustainable tyre materials is projected to grow from USD 35.5 million in 2022 to USD 700 million by 2029. To gain acceptance, however, any new material still has to meet the industry's "magic triangle": low rolling resistance, strong wet and dry grip, and high wear resistance.

Natural Rubber: Looking Beyond the Hevea Tree

The rubber tree, Hevea brasiliensis, still accounts for more than 98% of the world's natural rubber output. Researchers are exploring alternative sources, including Russian dandelion, which yields rubber of comparable quality to Hevea; guayule, which produces hypoallergenic rubber and whose tyres consume less energy over their life cycle (13.7 GJ per tyre versus 16.4 GJ); lettuce, which is convenient for genetic research; and goldenrod. Natural rubber certified under the Global Platform for Sustainable Natural Rubber (GPSNR) framework is gradually becoming an industry benchmark.

Bio-Based Synthetic Rubber and Fillers

Synthetic rubber production consumes tens of millions of tonnes of crude oil each year. Alternative elastomers are being developed from soybean oil, itaconic acid, β-myrcene, and sugar-fermented trans-β-farnesene. Some experimental products — such as silica/poly(itaconate-butadiene) nanocomposites — have shown good results for rolling resistance and wet grip, though independent verification against EU labelling standards is still needed.

Among fillers, green silica extracted from rice husk, bamboo leaves, and sugarcane bagasse is gradually replacing crystalline silica and conventional carbon black: producing one tonne of silica from rice husk requires only about a fifth of the coal and emits far less CO2 than conventional processes. Cellulose and lignin from wood and agricultural residues are also being studied as fillers, although their hydrophilic nature makes them difficult to combine with hydrophobic rubber. Carbon nanotubes (CNTs) and graphene recycled from waste tyre carbon black significantly improve tensile strength and wear resistance, but CNTs share a structural resemblance to asbestos, raising health concerns if released during wear or recycling — a concern that calls for a full life-cycle assessment.

Bio-Based Processing Aids and Fabrics

Various vegetable oils (palm, soybean, coconut, and others) are replacing petroleum-based process oils, improving wet grip and aging resistance. Cassava starch, soy protein, and lignin are also being tested as bio-based vulcanization accelerators. In fabrics, aramid fibers and lyocell (a regenerated cellulose fiber) are gradually replacing petroleum-based nylon and polyester in tyre carcasses and belts.

Recycled Materials

Ground rubber and reclaimed rubber from end-of-life tyres are being processed through devulcanization technologies for reuse, although the market for these materials remains fragmented and lacks unified standards. Some self-healing rubber compounds incorporating recycled rubber have achieved 80% healing efficiency while increasing tensile strength by 300%.

Steel accounts for 13–27% of a tyre's weight and is recovered through mechanical shredding and magnetic separation before being reprocessed via electric arc furnaces — a route that consumes less energy and can be 30–70% cheaper than producing new steel. Bridgestone has applied recycled steel in tyre bead wire, while a Michelin–Enviro joint venture aims to recover up to 90% of materials from end-of-life tyres.

For carbon black, the industry is developing several product lines in parallel: fully biomass-based renewable carbon black; recovered carbon black from used tyres (viewed by 65% of manufacturers as the ideal material for meeting sustainability goals); carbon black from methane pyrolysis; circular carbon black from tyre pyrolysis oil; and "green carbon black" made from biomass pyrolysis oil. In fabrics, recycled polyester from PET bottles (Continental's ContiRe.Tex technology can use up to 15 PET bottles per tyre) and recycled nylon from fishing nets are both seeing widespread use.

New Technologies and the Road Ahead

Artificial intelligence and life cycle assessment (LCA) are being used to optimize materials, design, and supply chains to cut carbon emissions across a tyre's entire life cycle. Notable emerging technologies include triboelectric tyres (which harvest energy from friction to improve electric vehicle efficiency), recyclable and self-healing vitrimer materials, 3D-printed puncture-proof tyres such as Michelin's Uptis, and airless tyres from Goodyear, BigRep, and Polaris.

Remaining Challenges

Researchers point to six main gaps: the long-term durability of new materials under real-world operating conditions; a fuller understanding of their degradability and environmental interactions across the life cycle, including the risk of microplastic release; balancing supply and demand while ensuring consistent raw material quality; the ability to scale up production at competitive cost; optimizing compatibility between hydrophilic bio-based fillers and hydrophobic rubber; and, finally, establishing standardized testing protocols and a unified regulatory framework for new materials.

Overall, the tyre industry is clearly shifting toward renewable and recycled materials, but moving from laboratory results to large-scale industrial application will still require years of further research along with a more coherent regulatory and technical-standards framework.

Source: Sampath, M.; Konikkara, N.; David, S.; Ramakrishnan, S.; Rath, J.P.; Amarnath, S.K.P. "Advancements in sustainable materials for environmentally responsible tyre production: a comprehensive review." RSC Sustainability, 2025.