Turning nature into fire shields: Biomass-based flame retardants for safer polymers

By harnessing the carbon-forming, nitrogen-releasing, and phosphorus-rich properties of these natural compounds, the team shows that safer and greener flame-retardant systems can be engineered. These findings pave the way for scalable, environmentally friendly solutions that enhance fire protection in critical applications such as construction, transportation, and textiles.

Fire safety remains a pressing challenge as highly flammable polymers are increasingly used in buildings, vehicles, and consumer goods. Traditional flame retardants, while effective, often rely on halogenated or fossil-based chemicals linked to toxicity, poor environmental compatibility, and limited sustainability. Recent catastrophic fires in iconic structures have underscored the risks of polymer combustion, which rapidly spreads flames and releases hazardous gases. Addressing these challenges requires new strategies that combine high flame resistance with environmental responsibility, leading researchers to explore biomass-based alternatives.

A study (DOI: 10.48130/emst-0025-0014) published in Emergency Management Science and Technology on 27 August 2025 by Qingsheng Wang’s team, Texas A & M University, provides a survey of how these natural substances can be modified and integrated into polymer matrices to deliver effective fire protection.

To evaluate biomass-derived flame retardants, the research team conducted a comprehensive review of both testing methods and application strategies. Methodologically, thermal and flammability behaviors were examined using standardized techniques: thermogravimetric analysis (TGA) to measure decomposition temperatures and char yield, limiting oxygen index (LOI) to assess the minimum oxygen required to sustain combustion, UL-94 vertical burning tests to classify flame resistance, microscale combustion calorimetry (MCC) to quantify heat release, and cone calorimetry to simulate real fire conditions and measure ignition, smoke production, and heat flux. Beyond laboratory testing, the methodology extended to assessing how starch, phytic acid, and chitosan can be incorporated into polymer matrices, either by physical blending with commercial flame retardants or by chemical modification to graft functional groups such as phosphorus- or nitrogen-containing moieties. These approaches allowed researchers to compare performance under both condensed-phase (char formation, barrier layers) and gas-phase (radical quenching, inert gas release) mechanisms. The results corresponding to these methodologies underscore the promise of biomass-based flame retardants. Starch, when combined with ammonium polyphosphate or melamine, demonstrated higher decomposition temperatures and char residue yields, while chemically modified starch derivatives achieved UL-94 V-0 ratings and significantly reduced peak heat release rates in polyurethane foams, polystyrene, and cotton fabrics. Phytic acid, particularly when coordinated with metal ions such as cobalt or nickel, improved char quality, suppressed toxic gas emissions, and elevated LOI values, with composites showing reductions of up to 60% in peak heat release rates. Chemical derivatives of phytic acid further enhanced compatibility with polymers and produced stable protective barriers. Similarly, chitosan-based systems, applied through layer-by-layer coatings or blended with phosphorus compounds, generated intumescent char layers and released non-combustible gases, improving both fire resistance and smoke suppression. Together, these findings confirm that, across multiple evaluation platforms, biomass-derived starch, phytic acid, and chitosan provide substantial and scalable improvements in polymer fire safety while aligning with sustainability goals.

The article concludes that starch, phytic acid, and chitosan represent abundant, low-cost, and renewable resources that can underpin the next generation of sustainable fire-safety materials. However, challenges remain in improving scalability, ensuring compatibility with high-performance polymers, and maintaining mechanical strength alongside flame retardancy. Future directions include multifunctional modifications that integrate water resistance, antimicrobial activity, or nanotechnology enhancements, as well as eco-friendly synthesis pathways. By bridging green chemistry with fire science, biomass-based flame retardants offer a promising route toward safer, more sustainable polymer products across multiple industries.

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References

DOI

10.48130/emst-0025-0014

Original Source URL

https://doi.org/10.48130/emst-0025-0014

About Emergency Management Science and Technology

Emergency Management Science and Technology (e-ISSN 2832-448X) is an open access journal of Nanjing Tech University and published by Maximum Academic Press. It is a medium for research in the science and technology of emergency management. Emergency Management Science and Technology publishes high-quality original research articles, reviews, case studies, short communications, editorials, letters, and perspectives from a wide variety of sources dealing with all aspects of the science and technology of emergency.