Nano Flame Retardant

Nano flame retardant system is a new type of polymer flame retardant system. The addition of a very small amount of nano flame retardant can significantly improve the combustion performance of polymer materials. Alfa Chemistry is committed to the continuous innovation and research of flame retardants (FRs), providing nanomaterials with flame retardant potential.

Classification

• One-dimensional nanomaterials: carbon nanotubes and various whiskers, such as magnesium salts and calcium sulfate whiskers.
• Two-dimensional nanomaterials: layered clay, such as montmorillonite (MMT), kaolite, graphite oxide (GO), layered doubled hydroxides (LDH) and so on.
• Zero-dimensional nanomaterials: nano aluminum hydroxide, magnesium hydroxide, titanium dioxide, silicon dioxide, polysilsesquioxane (POSS), fullerene (C₆₀), etc.

Features

Compared with traditional FRs, the most obvious feature of nano flame retardant system is that only a very small amount of nano flame retardant can be added to significantly improve the fire resistance of the material.

Besides, the introduction of nano FRs can also improve the mechanical properties of the material, while the addition of ordinary FRs will greatly affect the mechanical strength of the material.

Flame Retardant Mechanism

Barrier mechanism

At high temperature, the silicon oxide-like components formed by the decomposition of clay in the nanocomposite system migrate to the surface and participate in the formation of a barrier layer, which blocks the heat and mass transfer between the polymer surface and the external environment, thereby playing a flame retardant role.

Network structure and viscosity-increasing effect

The network structure can effectively inhibit the thermal motion of polymer molecular chains, increase the viscosity of the composite system, and prevent the escape of flammable gases formed by polymer degradation and the entry of external heat and oxygen, thereby effectively protecting the matrix.

Influence mechanism of network structure on polymer nanocomposites [1]

Free radical trapping mechanism

C₆₀ captures various free radicals and their derived free radicals generated by the degradation of polymer chains. On the one hand, this process interferes with the normal combustion of the polymer. On the other hand, this process causes the viscosity of the melt to increase sharply, which will subsequently cause the small molecular products generated by polymer degradation to require more energy and time to diffuse into the combustion zone, thus delaying the combustion.

Research Information

Wentao He et al. conducted a systematic review of the design, properties, applications, and challenges of polymer nanocomposites, focusing on the latest designs and properties of polymer nanocomposites. Besides, they proposed four basic design principles to fabricate flame retardant polymer nanocomposites, including multiple combinations and synergies, multiple mechanisms or modes of action, interfacial engineering, architectural design. Some of the potential applications of these advanced flame retardant polymer nanocomposites are summarized in the figure below. [2]

Potential applications of advanced FR polymer nanocomposites [2]

References

1. Ma HY, et al. (2011). "Flame retarded polymer nanocomposites: Development, trend and future perspective," Science China Chemistry 54(2), 302–313.
2. Wentao He, et al. (2020). "Flame retardant polymeric nanocomposites through the combination of nanomaterials and conventional flame retardants," Progress in Materials Science 114, 100687.