Breakthrough application of magnesium hydroxide in fireproof aluminum-plastic panels: dual innovation of environmental protection and performance

1. Pain points of traditional flame retardant materials and the rise of magnesium hydroxide

Traditional aluminum-plastic panels mostly use halogen flame retardants. Although this type of material can interrupt the combustion chain reaction by releasing halogen free radicals and effectively suppress the spread of flames, its fatal flaw is that it releases toxic gases such as hydrogen chloride and dioxins during combustion, which not only pollutes the environment but also may cause human poisoning

. With the tightening of global environmental protection regulations (such as EU REACH certification and China's "Building Fire Protection Design Code"), the market demand for non-toxic and low-smoke flame retardant materials has surged. In this context, magnesium hydroxide has become a technical breakthrough in the aluminum-plastic panel industry with its unique triple functions of "flame retardant-smoke suppression-environmental protection".

2. Flame retardant mechanism and performance advantages of magnesium hydroxide

The flame retardant effect of magnesium hydroxide comes from its thermal decomposition characteristics. When the temperature rises to 340℃, magnesium hydroxide quickly decomposes into magnesium oxide and water vapor. This process achieves dual protection through the following mechanisms:

1. Cooling effect: The decomposition reaction absorbs a large amount of heat (1137 kJ/g), significantly reducing the surface temperature of the material and delaying the thermal degradation of the polymer.

2. Dilution effect: The released water vapor dilutes the oxygen concentration, inhibits the combustion chain reaction, and at the same time, magnesium oxide covers the surface of the material to form a dense barrier, isolating oxygen from contact with combustibles.

3. Smoke suppression effect: The decomposition products of magnesium hydroxide can absorb smoke particles produced by combustion. A building materials company's actual measurement shows that the smoke density of aluminum-plastic panels with 30% magnesium hydroxide added is reduced by 50%, far exceeding traditional halogen flame retardants.

Compared with similar inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide has a higher decomposition temperature (340℃ vs. 220℃), can adapt to polymers with higher processing temperatures (such as high-temperature extruded polyethylene), and has a lower hardness, reducing wear on production equipment.

3. The environmental protection characteristics are reflected in the whole life cycle

The environmental protection advantages of magnesium hydroxide run through the whole process of raw materials, production and waste:

· Green raw materials: The abundant brucite ore (mainly magnesium hydroxide) in Liaoning, Shaanxi and other places in my country can be directly used to prepare flame retardants by mechanical grinding, with zero emissions in the whole process.

· Clean production process: The chemical synthesis method uses brine-ammonia reaction to avoid toxic by-products, and the hydrothermal method, precipitation method and other processes are gradually optimized, and energy consumption and costs continue to decrease.

· Degradable waste: Magnesium hydroxide can be decomposed into harmless magnesium oxide and water in the natural environment, and will not cause soil or water pollution. A certain company's aluminum-plastic panel has passed the EU REACH certification, confirming its eco-friendliness.

4. Practical application cases and performance verification

A well-known domestic building materials company uses the "magnesium hydroxide + polyethylene" composite core layer process to develop a new generation of fireproof aluminum-plastic panels:

· Flame retardant performance: The oxygen index is increased from the national standard 30 to 38, reaching the A2 fire protection standard, and the flame propagation rate is reduced by 60%.

· Physical properties: Through surface modification technology (such as silane coupling agent treatment), magnesium hydroxide is evenly dispersed in the substrate, solving the problem of sheet bulging caused by traditional filling, and the interlayer peeling strength is increased by 35%.

· Economic efficiency: Although the unit price of magnesium hydroxide is higher than that of aluminum hydroxide, its addition amount can be reduced by 20% (typical formula is 40%-60%), and the overall cost is reduced by 15%.

V. Technical Challenges and Solutions

Despite its significant advantages, the application of magnesium hydroxide still faces two major challenges:

1. Hygroscopicity leads to interface degradation: When the filling amount is high (>50%), magnesium hydroxide easily absorbs moisture, causing the aluminum plate and the core layer to peel off. Solutions include:

· Using nano-coating technology to form a hydrophobic layer on the surface of magnesium hydroxide;

· Compounding with hydrophobic flame retardants (such as zinc borate) to reduce the total addition amount.

2. Poor processing fluidity: Ultrafine magnesium hydroxide particles are easy to agglomerate, affecting extrusion molding. The powder with controllable particle size (1-5μm) prepared by microemulsion method can improve processing performance.

VI. Future Trends: Intelligence and Functional Integration

The industry is making breakthroughs in two directions:

1. Intelligent flame retardant system: Combine AI algorithm to monitor the combustion state in real time and dynamically adjust the decomposition rate of magnesium hydroxide, for example, by doping transition metal oxides (such as Fe₂O₃) to regulate thermal response characteristics.

2. Multifunctional integration: Compound magnesium hydroxide with graphene to give aluminum-plastic panels antistatic, electromagnetic shielding and other functions while flame retardant, expanding its application in 5G base stations, data centers and other scenarios.

The application of magnesium hydroxide marks a new stage for fireproof aluminum-plastic panels to move from "passive flame retardant" to "active protection". With the optimization of preparation process and innovation of composite technology, this green material is expected to fully ｒｅｐｌａｃｅ traditional flame retardants in building curtain walls, transportation and other fields, and promote the industry into a new era of high performance and sustainable development.