Melamine Polyphosphate (MPP) is a leading halogen-free nitrogen-phosphorus flame retardant, prized for its low toxicity, moderate addition levels, and dual-phase flame-retardant mechanism (condensed and gas phases). It is widely used in engineering plastics, rubber, and epoxy resins—especially in high-temperature-processed materials such as glass fiber-reinforced nylon 66 and polyester. This article details MPP’s synthesis, thermal stability, characterization, and applications for chemical engineers, material scientists, and flame-retardant manufacturers.
MPP is an eco-friendly flame retardant combining nitrogen and phosphorus, with unique structural and performance advantages:
Chemical Nature: Nitrogen-phosphorus (N-P) intumescent flame retardant, containing both acid source (phosphate groups) and gas source (melamine-derived nitrogen).
Physical Traits: White crystalline powder, non-halogen, low smoke emission, and compatible with most polymer matrices.
Flame-Retardant Mechanism:
Engineering plastics: Nylon 66, nylon 46, polyester, and glass fiber-reinforced composites (high processing temperatures require high thermal stability).
Rubber, epoxy resins, and polyesters: Used as an additive flame retardant to meet fire safety standards (e.g., UL94 V-0).
Early MPP synthesis methods suffer from poor thermal stability, low purity, or environmental issues, limiting industrial applicability:
To overcome traditional limitations, a modified two-step synthesis method is developed, focusing on catalyst addition and controlled temperature programming:
Preparation of Melamine Phosphate (MP)
Preparation of Melamine Polyphosphate (MPP)
The modified Melamine Polyphosphate’s structure and purity are confirmed by three key characterization methods:
Key Peaks: 3397 cm⁻¹ and 3165 cm⁻¹ (NH₂ and NH₃⁺ stretching vibrations), 1674 cm⁻¹ (C=N stretching vibration), 1063 cm⁻¹ (P=O stretching vibration), 881 cm⁻¹ (P-O-P stretching vibration)—consistent with MPP’s characteristic functional groups.
Resonance Peaks: δ -21.88 and δ -24.66 (P on the polyphosphate main chain), δ -9.72 (P at the polyphosphate chain end)—verifying the formation of target MPP.
The measured contents of C (17.45%), H (3.45%), N (40.80%), and P (14.76%) are consistent with theoretical values, confirming high product purity.
Performance Indicator | Modified Melamine Polyphosphate | Traditional Melamine Polyphosphate |
T₁% (℃) | 372.1 | 318.4–349.0 |
T₅% (℃) | 382.7 | 371.2–375.7 |
Char Residue (700℃, %) | 37.36 | 32.82–34.73 |
Purity | High (consistent elemental analysis) | Low (impurities from side reactions) |
Environmental Impact | Low (water as solvent) | High (organic solvents) |
Industrial Applicability | High (high yield, mild conditions) | Low (high cost, poor stability) |
The modified two-step synthesis method (catalyzed MP preparation + multi-stage calcination) produces MPP with superior thermal stability, high purity, and eco-friendliness. Its 1% weight-loss temperature of 372.1℃, 5% weight-loss temperature of 382.7℃, and 37.36% char residue at 700℃ make it ideal for high-temperature processed polymers such as nylon and polyester.
As the demand for halogen-free, high-performance flame retardants grows, modified MPP offers a reliable solution for balancing fire safety, environmental protection, and material performance. Its industrial applicability (high yield, low pollution) further solidifies its role as a leading flame retardant in the polymer industry.
Tech Blog Arc Resistance of Melamine Molding Compounds Melamine molding compounds are essential insulating materials for the electrical and instrumentation industries, widely used in mine
Tech Blog Influential Factors on Melamine Moulding Compounds Melamine moulding compounds are widely used in electronics, household utensils, and automotive parts due to their excellent
Tech Blog How to Slow Down Melamine Reactor Temperature Difference Rise Rate Melamine production via high-pressure processes (3rd-5th generation) relies heavily on reactor long-cycle operation.
JINGJIANG MELAMINE POWDER
© JINJIANG MELAMINE