Question

PEG400DO, polyethylene glycol 400 dioleate, what is this product? What are its main uses?

Answer
2026-06-06 官方文档 PEG400DO,聚乙二醇400双油酸酯

PEG400DO (Polyethylene Glycol 400 Dioleate) is a nonionic surfactant with an HLB value of approximately 8.5. Its core functions include acting as an emulsifier, dispersant, and wetting agent, widely used in textiles, industrial lubrication, metalworking, personal care, and agricultural chemicals.

Detailed Description

PEG400DO, with the full chemical name polyethylene glycol 400 dioleate (CAS No.: 9004-96-0), also known as PEG-8 Dioleate, is a diester-type nonionic surfactant produced by esterifying polyethylene glycol 400 with oleic acid. The product appears as a pale yellow to amber liquid, with a molecular weight of approximately 900–1000, a diester content of ≥90%, and an active ingredient content of ≥99%. Its molecular structure, featuring a hydrophilic polyethylene oxide chain (n≈8) and a lipophilic long oleic acid carbon chain, provides a balanced amphiphilic property, giving it a stable HLB value of around 8.5. It can serve as a water-in-oil (W\/O) emulsifier and also function as a secondary oil-in-water (O\/W) emulsifier in specific systems.

As a nonionic surfactant, PEG400DO exhibits good tolerance to acidic, alkaline, and hard water environments, with flexible compatibility that allows it to work with anionic, cationic, and other nonionic systems. Its critical micelle concentration (CMC) is approximately 1×10⁻⁴ mol\/L, and its surface tension is about 30 mN\/m (0.1% solution, 25°C), endowing it with excellent interfacial activity and wetting-spreading capability. The product has a cloud point of 40–50°C (1% aqueous solution) and is a low-foaming surfactant, making it suitable for processing scenarios requiring foam control. It should be noted that due to the presence of ester bonds in the molecule, it can hydrolyze under strong alkaline conditions and is therefore not suitable for high-alkalinity formulation environments.

This product is classified as a low-toxicity substance, with an acute oral LD50 > 5000 mg\/kg (rat), is easily biodegradable, and has a relatively low environmental impact. However, caution is still required as it may cause skin irritation, eye irritation, and respiratory irritation. According to GHS classification, it falls under skin irritation category 2, eye irritation category 2, and respiratory irritation category 3.

Technical Parameters

ParameterValue \/ Description
Chemical NamePolyethylene Glycol 400 Dioleate (PEG-8 Dioleate)
CAS No.9004-96-0
AppearancePale yellow to amber liquid
Ionic TypeNonionic
HLB Value8.5
Molecular Weight900~1000
Active Ingredient≥99%
Diester Content≥90%
Monoester Content≤5%
Acid Value≤5.0 mgKOH\/g
Saponification Value116~126 mgKOH\/g
Hydroxyl Value≤15 mgKOH\/g
Iodine Value55~65 gI₂\/100g
Moisture Content≤0.5%
pH Value (1% Aqueous Solution)5.0~7.5
Cloud Point (1% Aqueous Solution)40~50°C
Density1.11~1.13 g\/cm³
Kinematic Viscosity (25°C)100~200 mm²\/s
Refractive Index1.466~1.468
Flash Point>200°C
Surface Tension (0.1% Solution, 25°C)Approx. 30 mN\/m
Critical Micelle Concentration (CMC)Approx. 1×10⁻⁴ mol\/L
Foam CharacteristicsLow foaming
SolubilityDispersible in water; soluble in ethanol, acetone, and other organic solvents
Alkali ResistanceNot alkali-resistant; ester bond is prone to hydrolysis
Heavy Metals≤10 mg\/kg
Arsenic≤2 mg\/kg
Packaging Specifications50kg plastic drum \/ 200kg plastic drum \/ IBC tote

*The above parameter data are sourced from the Guoli Chemical Product Database.

Application Recommendations

With its balanced hydrophilic-lipophilic properties and versatile surface activity, PEG400DO excels in the following five key areas:

  • Textile Oils: Used as a key component in synthetic fiber spinning oils, providing excellent smoothness and emulsion stability, reducing friction damage during fiber drawing and winding, and improving the hand feel of the finished product. The recommended dosage depends on the oil formulation system and fiber type, typically accounting for 5%~20% of the total oil content.
  • Industrial Lubricants: Used in formulating water-soluble cutting fluids, hydraulic fluids, and extreme-pressure lubricants as an effective emulsifier and synergistic anti-rust component, helping the oil phase stably disperse in the water phase, extending fluid service life, and enhancing cooling and boundary lubrication performance. The recommended addition level is 5%~15% in water-based cutting fluid concentrates.
  • Metalworking Fluids: In processes such as turning, milling, grinding, and stamping, it promotes the formation of stable oil-in-water emulsions, reducing tool wear and improving machining accuracy and workpiece surface finish. It can be used in combination with nonionic and anionic emulsifiers to optimize emulsion stability.
  • Personal Care Products: Widely used in formulations such as facial cleansers, body washes, makeup removers, and shampoos as a mild emulsifying and moisturizing ingredient. It effectively removes impurities while keeping the skin hydrated, avoiding excessive degreasing, and imparting a silky after-wash feel. The recommended dosage is 1%~5%, and it can be blended with other nonionic surfactants to adjust the HLB value.
  • Agrochemical Formulations: Used in pesticide emulsifiable concentrates (EC), oil-in-water emulsions (EW), and microemulsions (ME) to enhance the dispersion stability of technical materials and their wetting and spreading ability on target surfaces, thereby improving efficacy. It is recommended to use in combination with emulsifiers of higher HLB values to meet the emulsification requirements of different solvent systems.

Additionally, PEG400DO can be extended to applications such as pigment dispersants, ink additives, and industrial cleaners, demonstrating its multifunctional surfactant advantages.

Precautions

  • Skin and Eye Protection: This product may cause skin irritation and serious eye irritation. Protective gloves, protective clothing, and eye protection should be worn during handling, and thorough washing should be performed after operation.
  • Respiratory Protection: It may cause respiratory irritation. Avoid inhaling vapors or mists. Wear a protective mask if necessary, and ensure good ventilation in the operating environment.
  • First Aid Measures: In case of eye contact, rinse cautiously with water for several minutes, removing contact lenses if present and continuing to flush. If eye irritation persists, seek medical attention promptly.
  • Storage and Stability: Chemically stable under normal storage conditions. Store sealed in a cool, dry place, avoiding high temperatures and strong alkaline environments (ester bond hydrolysis).