Polyethylene Glycol PEG-4000/6000 (CAS No.: 25322-68-3) is a nonionic high-molecular polymer polymerized from ethylene oxide, with the molecular formula HO(C₂H₄O)nH, where the degree of polymerization n is approximately 70~200, and the weight-average molecular weight ranges from 3400~6600. At room temperature, the product appears as a white waxy solid or granular form, with a melting point of about 50~63°C, and becomes a colorless transparent viscous liquid after melting. The effective content of the product is ≥99%, almost free of free alcohols and moisture, with an iodine value ≤1, indicating a highly saturated chemical structure and excellent oxidation stability.
This product is a nonionic surfactant with an HLB value as high as 18.9~19.0, strong hydrophilicity, easily soluble in water, and does not form micelles. It remains stable over a wide pH range and exhibits excellent tolerance to acids, alkalis, and hard water environments. Its acute oral toxicity LD₅₀ > 5000 mg/kg (rat), indicating it is practically non-toxic and safe. However, fine dust at certain concentrations in the air poses a risk of dust explosion, with a dust explosion class of St1; operations should be kept away from ignition sources and equipped with dust removal facilities.
Thanks to its unique molecular structure and physicochemical properties, Polyethylene Glycol PEG-4000/6000 plays an indispensable role in pharmaceuticals, daily chemicals, textiles, papermaking, metal processing, agriculture, and other fields. It can serve as an excellent emulsifier, wetting agent, dispersant, and solubilizer, while also providing ideal lubrication, moisture retention, and shaping functions, making it a key component in refined product formulations.
| Parameter Name | Value |
|---|---|
| Molecular Weight Range | 3400~6600 |
| Melting Point | 50~63 ℃ |
| HLB Value | 18.9 / 19.0 |
| Cloud Point | >100 ℃ |
| Active Content | ≥99% |
| pH (1% Aqueous Solution) | 5.0~7.0 |
| Hydroxyl Value | 8~16 |
| Density (Molten State) | 1.20~1.21 g/cm³ |
| Surface Tension (1% Aqueous Solution) | Approx. 55~60 mN/m |
| Kinematic Viscosity (100°C Molten) | Approx. 75~400 mm²/s |
| Acid Value | ≤0.1 |
| Saponification Value | ≤1.0 |
| Moisture | ≤1.0% |
| Iodine Value | ≤1 |
| Flash Point (Open Cup) | >240 ℃ |
| Heavy Metal Content | ≤10 ppm |
| Foam Characteristics | Low Foaming |
Pharmaceutical Field: Used as an ointment base, suppository base, and pill carrier, utilizing its suitable melting point and water solubility for uniform drug delivery; also can improve the dissolution rate and bioavailability of poorly soluble drugs. It is recommended to adjust the ratio of PEG-4000 and PEG-6000 based on specific drug formulations to regulate melting characteristics.
Daily Chemical Field: In toothpaste formulations, it can replace or partially replace glycerol as a humectant, with the recommended dosage adjusted according to the formulation system; in shampoos and body washes, it provides a smooth feel and reduces surfactant irritation; in cream and lotion skincare products, it serves as a basic moisturizing factor, forming a long-lasting hydrating film.
Industrial Applications: In the textile industry, used as an antistatic agent and lubricant for mercerizing treatment; in the rubber and plastic industry, as an efficient mold release agent and filler dispersant; in papermaking coating formulations, as a lubricant to prevent sticking to rolls; as a core component of metalworking quenching fluids, regulating cooling rates to reduce workpiece deformation and cracking; in pesticide formulations, as a carrier for water-dispersible granules, significantly improving pesticide suspension rates.