Triphenyl phosphate
[CAS# 115-86-6]

Identification

• Classification: Organic raw materials >> Inorganic acid ester
• Name: Triphenyl phosphate
• Synonyms: Phosphoric acid triphenyl ester; TPP
• Molecular Formula: C₁₈H₁₅O₄P
• Molecular Weight: 326.29
• CAS Registry Number: 115-86-6
• EC Number: 204-112-2
• SMILES: C1=CC=C(C=C1)OP(=O)(OC2=CC=CC=C2)OC3=CC=CC=C3

Properties

• Density: 1.29 g/mL
• Melting point: 47-53 ºC
• Boiling point: 370 ºC
• Flash point: 220 ºC
• Water solubility: insoluble 0.002 g/100g

Safety Data

• Hazard Symbols: GHS09 Warning
• Hazard Statements: H400-H410-H411
• Precautionary Statements: P273-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Eye irritation	Eye Irrit.	2	H319
Carcinogenicity	Carc.	2	H351
Skin sensitization	Skin Sens.	1A	H317
Reproductive toxicity	Repr.	2	H361d
Germ cell mutagenicity	Muta.	2	H341
Skin irritation	Skin Irrit.	2	H315

• Transport Information: UN 3077

Discovory and Applicatios

Triphenyl phosphate (TPP) is a chemical compound that has garnered widespread use as a flame retardant, plasticizer, and stabilizer in various industrial applications. Discovered in the early 20th century, TPP was initially developed as an additive to reduce the flammability of materials, particularly in the burgeoning field of plastics. Its flame-retardant properties, combined with its ability to improve the flexibility and durability of polymers, made it a versatile and widely adopted compound in industries ranging from electronics to construction.

The molecular structure of triphenyl phosphate consists of a central phosphorus atom bonded to three phenyl groups and one oxygen atom, forming a phosphate ester. This structure gives TPP its flame-retardant capabilities, as the compound can undergo thermal decomposition to release phosphorus-containing species that interfere with the combustion process. When exposed to heat, TPP acts by promoting the formation of a protective char layer on the surface of the material, reducing the release of flammable gases and slowing the spread of fire. This mechanism has made TPP an essential component in flame-retardant formulations for plastics, textiles, and coatings.

In the electronics industry, triphenyl phosphate is widely used as a flame retardant in electronic components and devices. With the increasing demand for consumer electronics and the miniaturization of devices, materials that are both flame-resistant and able to maintain electrical insulation properties are crucial. TPP is often incorporated into the plastic housings of electronic products, printed circuit boards, and other components to enhance their fire safety without compromising performance. Its compatibility with a variety of polymers, including polyvinyl chloride (PVC), polyurethane, and polystyrene, has contributed to its widespread adoption in this sector.

In addition to its flame-retardant properties, TPP also functions as a plasticizer, particularly in the production of flexible PVC products. As a plasticizer, TPP helps to improve the flexibility, workability, and durability of the polymer by reducing intermolecular forces between the polymer chains. This makes it easier to process and shape PVC into various forms, from cables and wires to flooring materials and automotive parts. The dual role of TPP as both a plasticizer and flame retardant is particularly advantageous in applications where enhanced fire resistance and material flexibility are required.

Beyond its use in plastics and electronics, triphenyl phosphate is employed in other industrial applications, such as lubricants and hydraulic fluids. Its stability under high temperatures and resistance to degradation make it suitable for use in demanding environments where thermal stability is critical. TPP is often used as an additive in synthetic oils and hydraulic fluids to enhance their performance and longevity, particularly in systems exposed to high heat or friction.

Despite its widespread use, the environmental and health effects of triphenyl phosphate have been the subject of increasing scrutiny. As an organophosphate compound, TPP has raised concerns due to its potential for bioaccumulation and toxicity in aquatic environments. Studies have shown that TPP can leach into the environment from consumer products, leading to its presence in water systems and sediments. In response, ongoing research aims to evaluate the long-term impacts of TPP on ecosystems and to develop safer alternatives or improve formulations to minimize its environmental footprint.

Triphenyl phosphate's discovery and development have had a profound impact on multiple industries, providing a solution for enhancing the fire safety and performance of various materials. Its continued use in flame retardants, plasticizers, and other applications highlights its versatility and effectiveness, although concerns about its environmental and health impacts are driving further research into sustainable alternatives. As industries evolve and prioritize safety and sustainability, TPP remains a significant chemical in the development of materials that meet modern standards for performance and environmental responsibility.