Piperazine Pyrophosphate|66034-17-1

Combining piperazine pyrophosphate with aluminum hypophosphite, MPP, or MCA flame retardants can reduce dosage and improve flame retardancy. Piperazine pyrophosphate, with the CAS number 66034-17-1 and abbreviated as PAPP or PPP, can be used in materials such as PP, PE, EVA, PA6/66, and TPE/TPU. Its chemical structure contains 22% phosphorus and 10% nitrogen. When combined with MPP, it can achieve V-0 halogen-free flame retardancy in PP. The resulting PP flame retardant exhibits excellent temperature resistance, precipitation resistance, thermal stability, and good machinability.

I. Product Introduction

Fully complies with environmental regulations such as RoHS and REACH. The material can achieve flame retardancy ratings such as UL94V-0 (0.75mm), GWTT750℃, and GWF1960℃, and pass the 70℃ x 168-hour flooding test (UL746C). Piperazine pyrophosphate is adaptable to a wide range of processing techniques and applications. It exhibits excellent precipitation resistance, low smoke density, and low toxicity. It exhibits good charring properties and high flame retardant efficiency, allowing it to be combined with a variety of flame retardants to achieve optimal flame retardancy. It also has a high thermal decomposition temperature and excellent heat aging resistance.

II. Basic Information

English Name: Piperazine pyrophosphate; PAPP; PPP

Chemical Formula: C4H14N2O7P2

Molecular Weight: 264.11

CAS Number: 66034-17-1

Appearance: White powder

Density: 1.71 g/cm³

Solubility: 12.24 g/L (20℃)

Stability: Excellent thermal, chemical, water, and light aging stability. Stable under normal storage and use conditions, not susceptible to decomposition or deterioration.

III. Product Specifications

Average Particle Size D50: 3-9 μm

Phosphorus Content: 22-24%

Nitrogen Content: 9-11%

Moisture Content: ≤0.5%

Whiteness: ≥93

True Density: 1.8 ± 0.1 g/cm³

Bulk Density: 0.5-0.8 g/cm³

TG1% Decomposition Temperature: ≥280℃ 

PH: 3-4

IV. Production Process

1. Piperazine Diphosphate Condensation Method

This method first synthesizes a piperazine diphosphate intermediate, which is then dehydrated and condensed to form piperazine pyrophosphate. This method produces a relatively high yield of piperazine pyrophosphate.

2. Sodium pyrophosphate is acidified to produce pyrophosphoric acid, which is then reacted with piperazine to produce piperazine pyrophosphate.

3. Double Decomposition Precipitation Method

Sodium pyrophosphate and piperazine are reacted in a hydrochloric acid solution to produce a water-insoluble piperazine pyrophosphate precipitate. However, due to the low solubility of the raw sodium pyrophosphate, the reaction solution concentration is very low during the synthesis process, resulting in a low yield of piperazine pyrophosphate.

V. Applications and Formulations

Piperazine pyrophosphate can be used in combination with MPP, MCA, hydroxides, and other materials. It is suitable for reinforced and unreinforced materials for thermoplastic resins such as PP, PE, EVA, TPE, and TPU. It can also be used in thermoset materials such as epoxy resins and unsaturated resins. 

1. PP flame retardant formula

Polypropylene (PP) content: 65-70 parts; piperazine pyrophosphate: 20-25 parts; aluminum hypophosphite: 3-5 parts; antioxidant (1010/168): 0.2-0.5 parts; lubricant: 0.5-1 part; talc: 2-5 parts. In 10%-30% fiber-reinforced PP, the piperazine pyrophosphate content should be increased to 25%-35% to offset the interference of glass fiber with carbon layer formation.

2. EP flame retardant formula for electronic potting compound

EP (E-51) content: 40-45 parts; curing agent (amine/anhydride): 10-15 parts; piperazine pyrophosphate: 20-25 parts; synergist (montmorillonite): 2-5 parts; diluent (butyl glycidyl ether): 3-5 parts. The cured material's oxygen index (LOI) can be increased to over 30, meeting UL94 V0 flame retardancy requirements. 

3. TPU Flame Retardant Formula

TPU (85A Hardness) 60-65; Piperazine Pyrophosphate 25-30; MCA Flame Retardant 5-8; Plasticizer (Phthalate) 2-3; Antioxidant 1098: 0.2-0.5

Note: The above data and formula are derived from laboratory data. The actual formula should be adjusted based on the flame retardancy requirements of the material, processing equipment, and material composition.

VI. Processing Precautions

1. Fillers and pigments in the piperazine pyrophosphate flame retardant system may have an adverse effect on flame retardancy. Calcium carbonate, carbon black, phthalocyanine green, etc., can reduce flame retardant efficiency or even render them ineffective. Verification is required before using fillers and pigments.

2. During processing, it is recommended to use a lower processing temperature, preferably not exceeding 230℃, provided the appropriate plasticizing effect is achieved.

VII. Packaging/Storage

25kg/bag: Transport as general chemicals. Store in a dry, cool place, away from direct sunlight.

Piperazine pyrophosphate achieves a triple flame retardant effect by providing acid, carbon, and gas sources during the combustion process. It exhibits a high decomposition temperature, is hydrolysis-resistant, and blends well with ammonium polyphosphate, MPP, and MCA, with minimal impact on the mechanical properties of plastics. Piperazine pyrophosphate can be used to flame-retard PP, PE, EP, PA6, EVA, TPE, and TPU. The addition of lubricants (such as zinc stearate and EBS) can prevent mold sticking and degradation during extrusion/injection molding. Thermal stability is particularly important during high-temperature processing (e.g., PP processing temperatures of 180-220℃). High addition levels (>30%) may reduce the tensile and impact strength of the material, which can be compensated by adding a small amount of toughening agents (such as POE) or reinforcing fibers. Piperazine pyrophosphate has low hygroscopicity, but when used in high-humidity environments, a moisture-proofing agent can be added to prevent caking and performance degradation.

 ---------------------------

Overseas Business Dept:  Armandliu: hxo@hxochem.com   Mb: +86-13358057724 (Whatsapp,WeChat)