A Brief Discussion on the Development of Flame Retardants (Part)

A Brief Discussion on the Development of Flame Retardants (Part)

Flame retardants have a history of over a century. From simple early-stage additives to modern technologies like microencapsulation and nano-synergy, technological iteration has never ceased. Let's now review this innovative journey of "fighting fire with fire."

Timeline of Flame Retardant Technology Evolution

I. 2007 and Before: Maturation and Initial Improvement of Traditional Technologies
This period focused on optimizing existing flame retardants and addressing their inherent shortcomings, such as compatibility, toxicity, and migration.

1. Surface Modification Technology (Widely adopted and continuously upgraded)

• Technology: Surface treatment of inorganic flame retardants (e.g., Aluminium Trihydroxide ATH, Magnesium Hydroxide MH) using coupling agents like silanes or titanates.

• Problems Solved: Improved compatibility between inorganic fillers and the polymer matrix, reducing negative impacts on the material's mechanical properties.

• Status circa 2007: A mature technology, considered standard practice for processing ATH/MH.

2. Microencapsulation Technology (Emerging and applied)

• Technology: Coating flame retardant monomers (e.g., red phosphorus) with inorganic or organic wall materials (e.g., resins).

• Problems Solved: Effectively prevented moisture absorption, oxidation, and release of highly toxic PH₃ gas from red phosphorus, improving its compatibility with the matrix.

• Status circa 2007: Recognized as an "efficient flame retardant treatment technology," successfully applied to red phosphorus.

3. Synergistic Blending Technology (Became an important R&D direction)

• Technology: Mixing different flame retardants to utilize synergistic effects (e.g., antimony-halogen, phosphorus-nitrogen, metal hydroxides with organosilicons) for a combined effect greater than the sum of their parts.

• Problems Solved: Reduced the required loading of single flame retardants, improved flame retardant efficiency, while also incorporating functionalities like smoke suppression and anti-dripping.

• Status circa 2007: Systems like N-P, and blends of Mg(OH)₂ with organosilicons were explicitly proposed and applied.

4. Polymerization/High Molecular Weight Technology (Proposed for organic flame retardants)

• Technology: Development of high molecular weight/polymeric organic phosphorus and bromine-based flame retardants (e.g., brominated epoxy resins, high molecular weight phosphates).

• Problems Solved: Addressed issues like migration, volatilization, and blooming common in small molecule flame retardants, enhancing durability and environmental friendliness.

• Status circa 2007: Recognized as an important development direction for replacing small molecule flame retardants.

II. 2007 - 2024: Rise and Deepening Development of New Technologies
In this period, cutting-edge technologies like nanotechnology became core drivers. Flame retardant design advanced to the molecular level and became more systematic, with environmental requirements turning into rigid demands.

1. Nanotechnology (Transitioned from lab to application, becoming the core upgrade)

• Technological Upgrade: Evolved from simple "super-refinement" to true nanostructuring.

Specific Manifestations:

• Nano-level Dispersion: Development of nano-layered silicates (e.g., Montmorillonite MMT), Carbon Nanotubes (CNTs), and nanofibers. These create a "labyrinth effect" through nano-dispersion in the matrix and form dense char layers for flame retardancy.

• Nano-hybrid Materials: Examples like POSS (Polyhedral Oligomeric Silsesquioxane), acting as a "molecular-level" modifying additive that can form a ceramic-like protective layer during combustion.

• Significant advantage: Even at extremely low addition levels, it significantly enhances flame retardancy while often improving the material's mechanical and thermal properties, overturning the conventional notion that flame retardants degrade the base material's performance.

2. Microencapsulation Technology (Expanded application scope and refinement)

Technological Upgrade: Expanded from primarily use with red phosphorus to treating other flame retardants (e.g., coating APP to improve water resistance). Coating materials and processes became more refined and diverse.

3. Development of New Eco-friendly Alternatives (From concept to reality)

Technological Upgrade: "Halogen-free" transitioned from a trend and appeal in 2007 to a practical R&D focus and market demand by 2024.

Specific Manifestations:

• Antimony Alternatives: Application technologies for synergists like Zinc Borate (ZB) and Zinc Stannate (ZS) became more mature.

• Efficient Halogen-free Systems: Research on Phosphorus-Nitrogen Intumescent Flame Retardants (IFR) deepened, focusing on solving issues like hygroscopicity and compatibility.

• Novel Organic Flame Retardants: Organosilicon flame retardants gained popularity due to high efficiency and low toxicity. Research on organoboron systems also made new progress.

4. Synergistic Blending Technology (Evolved towards systematization and multifunctionality)

Technological Upgrade: Progressed from simple binary blends to systematic flame retardant solutions involving multi-component, multi-mechanism synergism (e.g., N-P-Si-B element synergy), aiming to simultaneously meet multiple requirements like flame retardancy, smoke suppression, low toxicity, and mechanical properties.

Although Yinsu Flame Retardant is not a century-old establishment, we have personally witnessed the leaps in flame retardant technology over the past two decades — from microencapsulation to nano-synergy. We consistently uphold the philosophy of "accelerating R&D, upgrading performance," tailoring efficient and cost-effective flame retardant solutions for each client, ensuring safety and cost are no longer an either-or choice.