Innovative application of magnesium hydroxide flame retardant in industry

Magnesium hydroxide, white amorphous powder. Also known as caustic magnesite, lightly burned magnesia, etc., the suspension of magnesium hydroxide in water is called magnesium hydroxide emulsion, referred to as magnesium milk, and its English name is Magnesium hydroxide. Magnesium hydroxide is a colorless hexagonal prism crystal or white powder. The solubility in water is very small, but the water-soluble part is completely ionized. The concentration of the saturated aqueous solution was 1.9 mg / liter (18 ° C). Heating to 350 ° C loses water to form magnesium oxide. The natural mineral brucite of magnesium hydroxide. Can be used for sugar and magnesium oxide. Because magnesium hydroxide is abundant in nature, and its chemical properties are similar to aluminum, users have begun to use magnesium hydroxide instead of aluminum chloride for deodorant products. Used as analytical reagents and also in the pharmaceutical industry.

Magnesium hydroxide flame retardant is a kind of inorganic flame retardant for polymer matrix composites with good application prospects. Like aluminum hydroxide, magnesium hydroxide flame retardants rely on chemical decomposition to absorb heat and release water when heated to play a flame retardant role. Therefore, it has non-toxic, low smoke and magnesium oxide generated after decomposition. Produce secondary pollution and other advantages. However, compared with halogen-containing organic flame retardants, in order to achieve a considerable flame retardant effect, the filling amount should generally reach more than 50%. Because magnesium hydroxide is an inorganic material, the compatibility between the surface and the polymer base material is poor. Such a high filling amount, if it is not subjected to surface modification treatment, after filling into the polymer material, it will lead to composite materials The mechanical properties are degraded. Therefore, it must be surface-modified to improve its compatibility with the polymer base material, so that the mechanical properties of the filler material do not decrease, and even the mechanical properties of the material are improved.

As an important chemical product, magnesium hydroxide micro-nano materials have been widely used in ceramics, flame retardant, catalysis, medicine and environmental protection. The morphology, size, and dispersibility of magnesium hydroxide micro / nano materials will affect their application performance, so they need to be regulated. In the following, magnesium hydroxide is used as the research object, and the morphology, size and dispersibility of magnesium hydroxide products are successfully controlled by adjusting the synthesis conditions. Using magnesium hydroxide powder as one of the starting materials, an aluminum-magnesium composite coating was prepared by plasma spraying technology.

A process for preparing magnesium hydroxide micro-nano powders by ammonia diffusion method at room temperature was designed. Under the guidance of S042-ion and additive PEG, magnesium hydroxide micro-nanoparticles can crystallize into spherical crystals with good morphology. The effects of reaction concentration, reaction time, solvent and additives on the final morphology of the spherical product were studied through different comparative experiments. By changing the type of additives, the average diameter of the spherical crystals can be adjusted, so that it can meet the requirements of various specific applications. Also using an ammonia gas diffusion system, by changing the type of the magnesium salt reactant and the type of the additive, a magnesium hydroxide product different from the spherical shape can be obtained, that is, a sheet-like magnesium hydroxide with good dispersibility.