Christina Schenk, IMDEA MATERIALS

It’s possible that your home has polyester curtains, a synthetic fabric that can melt and burn quickly when it reaches high temperatures. Fire spreads across its surface and produces toxic smoke.

When a small flame comes into contact with polyester, the heat rapidly breaks down the fabric’s molecules and releases flammable gases. This flame quickly spreads along the vertical surface of the fabric and reaches considerable heights in seconds, generating dense black smoke, which is very toxic and dangerous.

This rapid spread can quickly engulf a room and hinder evacuation, turning simple curtains into a dangerous fire hazard in the home.

Like curtains, plastics are present in almost every aspect of our daily lives: textiles, electronic devices, automobiles, and construction materials. Although they are durable and versatile, they have a significant problem: their flammability.

However, in sectors such as electronics, flame-retardant plastics protect devices like TVs and computers; in automotive, they improve safety in dashboards and interior linings; and in construction, they are key for insulation and electrical conduits that prevent the rapid spread of fire. How do they gain this property?

Reducing risk

To reduce the risk of flammability, flame-retardant additives are used, chemicals that are added to plastics to make them less flammable.

These compounds help fire spread more slowly, giving more time to react and evacuate in case of fire. In fact, the effectiveness of these retardants can be measured with tests that evaluate how much the flame propagation speed is reduced. It is clear that houses and buildings with fire-resistant materials have greater fire safety than those that do not.

However, many conventional retardants derive from fossil sources and contain substances that can be harmful to health and the environment. Can we do better?

Toxicity and hormonal disruptions

For example, brominated flame retardants PBDEs (polybrominated diphenyl ethers), petroleum-derived, are found in furniture with foam, mattresses, and common household electronics. These compounds can release chemicals that irritate the eyes and skin. With prolonged exposure, they are associated with more serious health effects, such as hormonal disruptions, neurological damage, and an increased risk of some types of cancer. Dust released from these products is a common exposure route, especially for children.

Scientific studies have found that exposure to PBDEs is linked to cancer, endocrine disorders, and neurotoxicity in humans, which is why many countries are regulating or banning their use to protect public health.

Thus, although flame retardants improve fire safety, it is important to advance toward alternatives that are more sustainable and less harmful to health and the environment. How do we do that? We seek safer and more sustainable alternatives that not only reduce fire risk but also provide environmental benefits.

A new material with multifunctional applications

In this work, we present a new bio-based flame retardant system designed for polyamide compounds, a type of engineering plastic widely used for its strength and versatility. One application example is technical textiles, especially industrial or sports protective clothing, making them fire-resistant and safe while also caring for environmental impact.

However, this material also has huge potential in many other sectors, such as automotive, electronics, and packaging, expanding the range of high-performance materials with flame retardancy and low environmental impact, useful for various industrial applications.

Mechanical strength in these garments is essential because they must withstand continuous stresses, such as rubbing, abrasion, and impacts, over long periods of use in demanding conditions. This way, the clothing maintains its integrity, does not easily get damaged, and continues to effectively protect the user against thermal or chemical risks for longer.

Smart materials

What’s truly innovative is not only the choice of renewable materials but also the design and optimisation method we used: a strategy combining laboratory experimentation with machine learning tools and optimisation algorithms.

The usual process was “trial and error,” where different chemical combinations were prepared, tested in the lab, and their properties measured to determine which performed best. But this method consumes much time and resources due to the many tests needed to find an optimal formula.

In our work, we applied a data-driven approach that allows us to design experiments systematically to explore different combinations. We use AI models that learn from experimental data and predict the performance of new formulations, and generate optimisation methods that identify the most promising solutions. Using AI lets us speed up the discovery process.

Thanks to this approach, we simultaneously improved the mechanical strength and safety (two properties that often conflict) of the new biomaterial we sought.

The best possible biomaterial

The best biomaterial created showed an 18.4% increase in tensile strength (the ability to withstand stress before breaking) and a 53.1% reduction in the peak heat release rate, a key parameter in fire behaviour. This advance is relevant, for example, in more sustainable and healthier high-performance textiles.

By combining experimental science with artificial intelligence, we reduce dependence on harmful additives, minimise waste, and pave the way for new safe, sustainable, and high-performance materials that bring direct benefits to society.

Christina Schenk, Postdoctoral researcher in machine learning for materials science applications, IMDEA MATERIALS

This article was originally published in The Conversation. Read the original (content in Spanish).