Study on the flame retardant properties of polypropylene enhanced by magnesium hydroxide
In the field of materials science and polymer chemistry, magnesium hydroxide (Mg(OH)₂) is an excellent inorganic flame retardant. Due to its excellent flame retardant efficiency and environmentally friendly properties, its application in polymer materials such as polypropylene (PP) has attracted much attention.
Characteristics of polypropylene
Flammability: The low melting point and high flammability of polypropylene require flame retardant treatment in specific applications.
Widely used: As a preferred material for automotive interiors, home appliance housings, packaging materials, etc.
Flame retardant mechanism of magnesium hydroxide
Endothermic decomposition: Magnesium hydroxide decomposes at high temperatures, absorbs heat, and reduces the surface temperature of the polymer.
Isolation of oxygen: The generated water vapor and magnesium oxide form a protective layer, which isolates oxygen and inhibits combustion.
Smoke suppression: Magnesium hydroxide produces almost no harmful gases and smoke during decomposition.
Synergistic flame retardant system
Application of synergists: Magnesium hydroxide is used together with synergists such as antimony trioxide (Sb₂O₃) and phosphates to enhance the flame retardant effect.
Surface modification: Silane coupling agent, stearic acid, etc. are used to modify the surface of magnesium hydroxide to improve its compatibility with polypropylene and flame retardant efficiency.
Experimental method
Mixed preparation: Magnesium hydroxide and polypropylene are mixed to prepare composite materials by co-extrusion and other technologies.
Performance test: Flame retardant properties are evaluated by vertical burning test (UL-94), limiting oxygen index (LOI), thermogravimetric analysis (TGA), etc.
Results and discussion
Improved flame retardant properties: The addition of magnesium hydroxide significantly improves the flame retardant properties of polypropylene, the LOI value is increased, and the vertical burning grade is improved.
Mechanical properties consideration: Magnesium hydroxide may affect the impact strength of the material, and reasonable proportioning and surface modification can reduce the negative impact.
Environmental advantages: Magnesium hydroxide is non-toxic and harmless, and does not produce toxic smoke when burned, meeting environmental protection requirements.
Application prospects
Automotive industry: Used for automotive interior parts to enhance safety.
Electronic appliances: As a shell material for electronic equipment, ensure safe use.
Building materials: Produce fire doors, fireproof boards, etc. to improve building safety.
The synergistic use of magnesium hydroxide and polypropylene not only significantly improves the flame retardant properties of the material, but also maintains good mechanical properties. Through formula design and surface modification technology, the flame retardant effect of magnesium hydroxide has been optimized and is expected to be more widely used in multiple fields.