Flame retardant performance of composite material is determined by the synergistic action between all components,The more uniformly the flame retardant is dispersed in the composite material, the better the flame retardant performance of the composite material. The stronger the force between the flame retardant and the matrix resin, the stronger the heat resistance of the composite material, the flame resistance is also improved.
Meanwhile, the synergistic char formation effect between organic modifier and inorganic flame retardant can also improve the fire resistance.
The effect of different modifier to oxygen index and smoke density
People also did research on the effect of stearic acid adding amount to oxygen indiex and smoke density, and the resultes shows that along with the adding of stearic acid, the oxygen index decreased, flame rating of composite system also became worse. because stearic acid is inflammable, and combination with EVA is worse, so surface modifier will fall off when adding too many or being heated. so the data of stearic acid modified has low oxygen index and higher smoke density.
Silane coupling agent is easy to condense itself to form oligomer, and also form Interpenetrating polymer structure with matrix resin. When the composite material system is heated and burned, the oxane structure is easy to form carbon, which can slow down heat conduction into the system. At the same time, the porous carbon layer formed on the surface of the system can absorb part of the burning ashes, thus reducing the smoke density of the system. So silane modified MDH/EVA has higher oxygen index and lower smoke density.
Above statistics is for your reference, and you can choose the most suitable modifier based on your cable formulation. KMT Industrial Ltd., manufactures modified magnesium hydroxide that caters to difference applications, so please feel free to contact for more information.
Thank you for your time, and Take Care.