Preparation of magnesium hydroxide flame retardant by phase chemistry: technology and application
As an efficient and controllable magnesium hydroxide preparation technology, liquid phase chemical method has significant advantages in the production of high-performance flame retardants. This article will introduce the key steps and technical points of liquid phase chemical method in detail.
Key technologies and steps
Raw material selection
Magnesium source: Soluble magnesium salts such as magnesium chloride and magnesium sulfate are selected.
Precipitant: Sodium hydroxide, ammonia water, etc. are used to generate magnesium hydroxide precipitation.
Surface modifier: Polyvinyl alcohol, fatty alcohol polyoxyethylene ether, etc., to improve the dispersibility and compatibility of magnesium hydroxide.
Preparation process
Solution preparation: Dissolve magnesium salt to form a solution of a specific concentration.
Precipitation reaction: Control the morphology and size of the product by dropping the precipitant.
Morphology control: Add morphology control agents such as SDS or trisodium citrate to obtain a specific morphology.
Surface modification: Add modifiers during the reaction to improve the performance of magnesium hydroxide.
Post-treatment
Washing: Remove residual salts and impurities in the precipitate.
Filtration: Separate solid magnesium hydroxide and liquid.
Drying: Dry at a suitable temperature to remove moisture.
Crushing: Adjust the magnesium hydroxide to the required particle size.
Influencing factors
Reaction temperature, pH value, time, stirring speed, etc. all have an important influence on the performance of the product.
Performance test
Flame retardant performance: evaluated by LOI test and vertical burning test.
Thermal stability: evaluated by TGA and DSC methods.
Dispersibility and compatibility: observe the dispersion in the polymer matrix by microscope.
Application field
Polymer materials: as a flame retardant for plastics, rubber, fiber and other materials.
Coatings and paints: as a key component of fire retardant coatings.
The liquid phase chemical method provides an efficient and controllable method for the preparation of magnesium hydroxide flame retardant. By precisely controlling the reaction conditions and post-processing steps, magnesium hydroxide products with excellent flame retardant properties and good dispersibility can be obtained. With the continuous advancement of technology and the growth of market demand, magnesium hydroxide flame retardants prepared by liquid phase chemical method will play an important role in many fields.