Hebei Messi Biology Co., Ltd. stated that natural hydromagnesite (hydromagnesite compound flame retardant) is a new type of high temperature resistant flame retardant. Under the action of heat, it can release water and CO2 successively. These decomposition and release processes can absorb a lot of heat, thereby reducing the temperature of the flame on the surface of the flame retardant polymer material, delaying its degradation or making it difficult to burn; the water vapor and CO2 produced at the same time can cover the flame and reduce the concentration of combustible gas and oxygen in the combustion zone; in addition, the remaining MgCO3, Mg(OH)2 and MgO can form a heat transfer barrier layer on the polymer surface, hindering the continued decomposition of the polymer matrix and preventing dripping.
· Release water at a temperature of about 220°C (thermal decomposition)
· Release carbon dioxide at a temperature of about 330°C
· At a temperature of about 560°C, hydromagnesite particles gather on the surface of the burning polymer to form a stable cement-like coke layer, thereby inhibiting the combustion process and the spread of the flame through the burning drippings.
· Hydromagnesite can be completely decomposed at 727°C and converted into magnesium oxide, carbon dioxide and water. Among them, magnesium oxide has high fire resistance and insulation properties. It can be transformed into crystals after high temperature burning above 1000℃. When it rises to 1500-2000℃, it becomes dead burned magnesium oxide (also known as magnesia) or sintered magnesium oxide.
Natural hydromagnesite is a low-smoke, halogen-free inorganic mineral flame retardant, which is widely used in various polymers, such as PE, PP, EVA, PVC, silicone rubber and other various synthetic resins and rubbers, etc. It can also be used in coatings and building materials flame retardant, with a filling amount of about 15-60%.
When the amount of natural hydromagnesite reaches 60wt% of the total mass of the composite material, the limiting oxygen index of the synergistic PE flame retardant composite material is 28%, the vertical combustion level reaches UL94V-0 level, and the tensile strength reaches 28.8MPa.