Preparation of magnesium hydroxide flame retardant by liquid phase chemical method: technological innovation and application prospects

Magnesium hydroxide (Mg(OH)₂) is a highly efficient inorganic flame retardant. It has broad application prospects in the field of polymer materials due to its green, environmentally friendly, safe and non-toxic characteristics. Liquid phase chemical method is an effective means to prepare magnesium hydroxide. By precisely controlling the chemical reaction conditions, magnesium hydroxide products with specific properties can be prepared.

Preparation principle of liquid phase chemical method

The basic principle of liquid phase chemical method is to generate magnesium hydroxide precipitate through the chemical reaction of magnesium salt and alkaline substances in aqueous solution. The typical chemical reaction equation is as follows: MgCl2+2NaOH→Mg(OH)2↓+2NaClMgCl2+2NaOH→Mg(OH)2↓+2NaCl

Preparation method

· Raw material selection: Use magnesium chloride hexahydrate (MgCl₂·6H₂O) and sodium hydroxide (NaOH) as the main raw materials.

· Dispersant: Add sodium dodecyl sulfate (SDS) and ethanol to control the particle size distribution of the product.

· Reaction conditions: including the order of feeding, the amount of dispersant, the reaction temperature, the concentration ratio of the reactants, etc., all have an important influence on the performance of the product.

· Post-treatment: including washing, filtering, re-slurry treatment, drying and grinding to improve the purity and dispersibility of the product.

Performance study

· Particle size and absorbance: study the effect of particle size on absorbance.

· Micromorphology: observe the microstructure of the product using a scanning electron microscope (SEM).

· Crystal structure: analyze the crystal properties of the product by X-ray diffraction (XRD).

Application prospects

As an excellent flame retardant, magnesium hydroxide can absorb heat and release water vapor when it is thermally decomposed, effectively slowing down the spread of flames. Its decomposition product magnesium oxide (MgO) can also form a protective layer on the surface of the material, further improving the flame retardant effect.

Research progress

· Low-cost multi-shape nano magnesium hydroxide: by optimizing the preparation conditions, the preparation of low-cost, multi-shape nano magnesium hydroxide flame retardant is achieved.

· Synthesis of highly dispersed and fine magnesium hydroxide: Study the effects of different conditions on the particle size and absorbance of the product, and perform morphology and structure analysis by SEM and XRD.

· Pyrolysis-hydration preparation technology: A new method of preparing highly active magnesium oxide by direct dynamic pyrolysis and then hydrating to prepare magnesium hydroxide is proposed to simplify the process flow and reduce costs.

Liquid phase chemical method has shown significant advantages in the preparation of magnesium hydroxide flame retardants. By precisely controlling the reaction conditions, magnesium hydroxide products with specific morphology and properties can be prepared. This method provides an effective solution for the flame retardant field of polymer materials and has good market application potential.