Inorganic flame retardants are non-toxic, environmentally friendly, and low-priced, which are commonly used flame retardants for polymer flame retardants. Basic magnesium carbonate (crystal structure Mg5[(CO3)4(OH)2]*4H2O) has good thermal stability, non-toxic, no toxic or volatile gas, low price, and is an inorganic environmentally friendly flame retardant.
Basic magnesium carbonate (thermal decomposition temperature 220~550℃) has a wider thermal decomposition temperature range than magnesium hydroxide (thermal decomposition temperature 300~340℃) and aluminum hydroxide (thermal decomposition temperature 180~200℃). After the basic magnesium carbonate is burned, it decomposes and absorbs heat, releases the refractory gas CO2 and water vapor, dilutes the oxygen on the surface of the combustion product and reduces the surface temperature of the combustion product, and generates active magnesium oxide attached to the surface of the combustion product to further prevent the combustion from proceeding. When it is applied to flame-retardant epoxy resin, when the addition amount of basic magnesium carbonate is 56.5%, the oxygen index of epoxy resin reaches 29.7%. It is applied to the flame-retardant ethylene/ethylene acetate copolymer. When the addition amount of basic magnesium carbonate is 60%, the oxygen index of the ethylene/ethylene acetate copolymer reaches 29%.
When using inorganic flame retardant flame retardant polymers, in order to obtain ideal flame retardant properties, a larger amount of addition is often required, and the hydrophilicity of inorganic flame retardants will increase the processing difficulty of the polymer and reduce the mechanical properties. Conducive to actual production and application. Surface modification of flame retardants is an effective means to increase the compatibility of inorganic fillers with polymer matrix.