Natural hydromagnesite (hydromagnesite compound flame retardant) Hydromagnesite is a new type of high temperature resistant flame retardant, which can release water and CO2 successively under the action of heat. These decomposition and release processes can absorb a lot of heat, thereby reducing the flame retardant. The temperature of the flame on the surface of the burning polymer material can delay its degradation or make 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 and Mg(OH)2 can be decomposed And MgO, etc. can form a heat and mass transfer barrier layer on the surface of the polymer, hindering the continued decomposition of the polymer matrix and preventing droplets.
releases moisture at approximately 220°C (thermal decomposition)
Releases carbon dioxide at a temperature of about 330°C
· At a temperature of about 560°C, hydromagnesite particles aggregate 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 burning droplets.
·Hydromagnesite can be completely decomposed at 727°C and converted into magnesium oxide, carbon dioxide and water. Among them, magnesium oxide has high refractory and insulating properties. It can be transformed into crystals by burning at a high temperature above 1000 ° C, and it can become dead-burned magnesium oxide (that is, the so-called magnesia) or sintered magnesium oxide when it rises to 1500-2000 ° C.
Natural hydromagnesite is a low-smoke, halogen-free inorganic mineral flame retardant, widely used in various polymers, such as PE, PP, EVA, PVC, silicone rubber and other synthetic resins and rubbers etc. It can also be used in coatings and flame retardant building materials. The filling amount is about 15-60%.
When the amount of natural hydromagnesite reached 60wt% of the total mass of the composite, the limiting oxygen index of the synergistic PE flame-retardant composite was 28%, the vertical combustion level reached UL94V-0, and the tensile strength reached 28.8MPa.