Hebei Messi Biology Co., Ltd. stated that basic magnesium carbonate was surface modified with stearic acid and added to a mixture of low-density polyethylene (LDPE) and ethylene-vinyl acetate (EVA) to prepare flame-retardant composite materials. The effect of basic magnesium carbonate on the flame retardancy and mechanical properties of LDPE/EVA was studied. Scanning electron microscopy (SEM) and thermal weight loss (TG) were used to characterize the micromorphology and thermal properties of the flame-retardant composite materials, respectively. The results show that after surface modification, basic magnesium carbonate changes from hydrophilic to lipophilic. When the amount of basic magnesium carbonate added is 150 parts, the tensile strength of the flame-retardant composite material is 13.1MPa, and the bending strength is 13.1MPa. The strength is 5.0MPa, the impact strength is 3.27kJ/m2, the elongation at break is 9.4%, and the oxygen index is 31.6%.
Polyethylene is a flammable polymer with an oxygen index of 17% to 18% and a combustion heat value of 45.9MJ/kg, which is relatively high among polymer materials. Polyethylene is often used as coatings for wires and cables, pipe linings, foam materials, and in many cases as building materials. Therefore, there are certain requirements for the flame retardancy of polyethylene, especially when used for wires and cables. More stringent. The decomposition temperature of basic magnesium carbonate is 200~550°C, which is wider than that of magnesium hydroxide and aluminum hydroxide. After burning, basic magnesium carbonate decomposes and absorbs heat, releasing refractory gases CO2 and water vapor, diluting the oxygen on the surface of the combustion material and The temperature of the surface of the burning material is lowered, and active magnesium oxide is generated that adheres to the surface of the burning material, further preventing the combustion from proceeding.
Magnesium carbonate is applied to flame-retardant epoxy resin. When the addition amount of basic magnesium carbonate is 56.5%, the oxygen index of the epoxy resin reaches 29.7%. By adding magnesite, basic magnesium carbonate and basic magnesium carbonate/carbonite to EVA and EEA, the flame retardant properties have been greatly improved. Basic magnesium carbonate has more advantages than magnesium hydroxide in reducing flammability, so it has attracted more and more people’s attention. However, excessive inorganic filler content will have a serious impact on the mechanical properties of flame-retardant composite materials. EVA is soft and has good impact resistance, making it easy to form and process.
Hebei Messi Biology Co., Ltd. stated that it used stearic acid to surface modify basic magnesium carbonate and added it to LDPE/EVA. It discussed the impact of different addition amounts of basic magnesium carbonate on the flame retardant performance of flame retardant composite materials. and mechanical properties.