Effect of phosphorus-containing flame retardants on the combustion properties of high-impact polystyrene/magnesium hydroxide composites
High-impact polystyrene (HIPS) plays an important role in many fields due to its excellent impact resistance and processing properties. However, its higher flammability limits its performance in applications with strict fire protection requirements. In order to improve the flame retardant properties of HIPS, researchers began to explore the possibility of compounding phosphorus-containing flame retardants with magnesium hydroxide (Mg(OH)₂). This article will analyze in detail the effect of phosphorus-containing flame retardants on the combustion performance of HIPS/magnesium hydroxide composites.
The mechanism of action of phosphorus-containing flame retardants
Phosphorus-containing flame retardants play a key role in the combustion process. They can form phosphate esters and phosphates under high temperature conditions, and further decompose to form phosphoric acid and phosphorus oxides. These substances form a non-combustible protective film on the surface of the material, effectively isolating oxygen and heat and inhibiting the spread of flames. At the same time, phosphorus oxide can also promote the decomposition of magnesium hydroxide to generate more water vapor, which can cool and dilute combustible gases, further enhancing the flame retardant effect.
Effect on HIPS/magnesium hydroxide composites
Limiting Oxygen Index (LOI)
Research shows that the addition of phosphorus-containing flame retardants significantly increases the LOI value of HIPS/magnesium hydroxide composites, indicating that its flame retardant properties have been significantly improved.
Heat Release Rate (HRR)
The addition of phosphorus-containing flame retardants can reduce the peak heat release rate of HIPS/magnesium hydroxide composite materials, delay the heat release process, and reduce the risk of fire spread.
Smoke density and toxic gas emissions
Although phosphorus-containing flame retardants may increase the emission of smoke and toxic gases during combustion, at a reasonable compounding ratio, their positive effects on the overall combustion performance of HIPS/magnesium hydroxide composites outweigh their negative effects.
Mechanical behavior
The addition of phosphorus-containing flame retardants may have a certain impact on the mechanical properties of composite materials, but by optimizing the formula, the negative impact on the strength and toughness of the materials can be minimized.
The combined use of phosphorus-containing flame retardants and magnesium hydroxide can significantly improve the flame retardant properties of HIPS composite materials. Effectively inhibits flame spread by forming a protective film and increasing the cooling effect of thermal decomposition products. In practical applications, by finely regulating the type and amount of phosphorus-containing flame retardants, a balance between flame retardant properties and basic material properties can be achieved, providing wider application prospects for HIPS composites in fields with higher fire protection requirements. .
Through in-depth research on the combined use of phosphorus-containing flame retardants and magnesium hydroxide, HIPS composite materials can provide wider application prospects in fields with higher fire protection requirements. Improvements to this material not only improve its flame retardant properties but also enable it to meet more stringent fire protection standards while maintaining its basic mechanical properties.