Study on the synergistic effect of ammonium polyphosphate-magnesium hydroxide composite flame retardant

Halogen-free flame retardants are valued for their environmental friendliness. Ammonium polyphosphate (APP) and magnesium hydroxide (Mg(OH)₂) are representative halogen-free flame retardants that can improve the flame retardancy of materials while also improving physical properties. This study explores the combined use of these two flame retardants and their synergistic effects.

Synthesis of ammonium polyphosphate-magnesium hydroxide composite flame retardant

Synthesis of ammonium polyphosphate

It is prepared by polymerization reaction of raw materials such as phosphoric acid and urea.

Preparation of magnesium hydroxide

Prepared by brine method or other precipitation methods.

Preparation of composite flame retardant

Mix APP and Mg(OH)₂ in proportion, and may add surface modifiers, and mix evenly by high-speed mixer.

Test the performance of composite flame retardant

Thermal stability test

TGA is used to evaluate the thermal stability of composite flame retardants at different temperatures.

Flame retardant performance test

Flame retardant performance is evaluated by UL 94, LOI and CONE tests.

Mechanical property test

Evaluate the effect of adding composite flame retardants on the mechanical properties of materials.

Compatibility test

Observe the microstructure and test the interface bonding strength to evaluate the compatibility.

Endothermic decomposition behavior

Analyze the decomposition behavior at high temperature to understand the endothermic effect.

Heat release rate (HRR)

Measure the HRR during combustion using a cone calorimeter.

Experimental design example

Prepare composite flame retardant samples with different ratios.

Mix the composite flame retardant with the matrix material to prepare the composite material.

Perform performance tests on the composite material to compare the effects of different ratios.

The composite use of ammonium polyphosphate and magnesium hydroxide can significantly improve the flame retardant effect, reduce the amount of a single flame retardant used, and broaden its application prospects in multiple fields by improving physical properties. By fine-tuning the composite ratio and reaction conditions, the performance of the composite flame retardant can be optimized to meet the needs of specific applications.