Magnesium hydroxide is a new type of filled flame retardant. It releases bound water when it is decomposed by heat absorbs a large amount of latent heat to reduce the surface temperature of the synthetic material it fills in the flame. The generated combustible gas is used for cooling.

Magnesium hydroxide is an inorganic flame retardant filler for polymer-based composite materials with good application prospects. Like aluminum hydroxide, magnesium hydroxide flame retardant relies on the chemical decomposition of heat releases water when heated to play a flame retardant effect, so it has non-toxic, low smoke magnesium oxide generated after decomposition is chemically stable, There are advantages such as secondary pollution. However, compared with halogen-containing organic flame retardants, to achieve a comparable flame retardant effect, the filling amount should generally reach more than 50%. Since magnesium hydroxide is an inorganic substance, the compatibility between the surface the polymer base material is poor, such a high filling amount, if it is subjected to surface modification treatment, after filling into the polymer material, it will lead to composite materials The mechanical properties are reduced. Therefore, it must be surface-modified to improve its compatibility with the polymer base material, so that the mechanical properties of the filler material does decline, even partially improve the mechanical properties of the material.

The experiment proves that unmodified magnesium hydroxide exists in the form of agglomerates in PP. Although the powder itself is very fine, there is a clear difference between the particle agglomerates the PP matrix due to the incompatibility of the particle surface with the PP matrix. The boundaries are even empty. The voids formed after the magnesium hydroxide particles escaped during brittle fracture indicate that the unmodified magnesium hydroxide only acts as a filler flame retardant in PP, does chemically bond with PP. The surface-modified magnesium hydroxide is evenly dispersed in the PP matrix, the particles are mostly dispersed in the material in the form of primary particles small agglomerated particles.