Polyethylene Glycol PEG-4000/6000 (CAS No.: 25322-68-3) is a classic nonionic high molecular polymer produced by Haian Guoli Chemical Co., Ltd., also known as Macrogol 4000/6000, Polyethylene Glycol 4000/6000, Carbowax 4000/6000, and Polyoxyethylene 4000/6000. The main difference between PEG-4000 and PEG-6000 lies in their molecular weight grades, with the numbers representing their average molecular weight ranges. The difference in molecular weight leads to distinctions in melting point, viscosity, and specific application scenarios.
This series of products has three core advantages: First, excellent compatibility — it has outstanding emulsifying, wetting, dispersing, and solubilizing capabilities, effectively improving the stability and uniformity of formulations; Second, superior chemical stability — it remains stable over a wide pH range and exhibits excellent tolerance to acids, alkalis, and hard water; Third, good functionality — it provides ideal lubrication, moisturization, and excipient functions, making it a key component in refined product formulations. Its acute oral toxicity LD50 is greater than 5000 mg/kg (rat), classifying it as practically non-toxic, with a flash point (open cup) greater than 240°C.
In terms of physical and chemical form, PEG-4000/6000 is a solid waxy flake with strong hygroscopicity, requiring sealed storage to prevent moisture absorption during handling and storage. Its dust, when mixed with air at certain concentrations, may pose an explosion risk (dust explosion class St1), so appropriate ventilation and dust collection systems should be installed in the production environment, and sources of ignition should be avoided.
| Parameter | PEG-4000/6000 Specification |
|---|---|
| Product Type | Nonionic high molecular polymer (surfactant) |
| Appearance | White to slightly yellow waxy solid or flakes |
| CAS No. | 25322-68-3 |
| Ionic Type | Nonionic |
| pH Stability | Stable over a wide pH range, resistant to acids, alkalis, and hard water |
| Flash Point (Open Cup) | > 240°C |
| Acute Oral Toxicity LD50 | > 5000 mg/kg (rat), practically non-toxic |
| Dust Explosion Class | St1, minimum ignition temperature of dust cloud > 400°C |
| Hygroscopicity | Strong hygroscopicity, requires sealed storage |
| Hazard Classification | Non-hazardous substance or mixture (GHS and EC No 1272/2008) |
With its multifunctional properties, PEG-4000/6000 has established and widespread applications in the following industries:
1. Pharmaceutical Industry: Used as an ointment base, suppository base, and drip pill carrier, leveraging its suitable melting point and good water solubility to achieve ideal drug release profiles; also used as a solubilizer and stabilizer in injections or oral liquid formulations to improve drug solubility and long-term storage stability. Particularly suitable as a water-soluble solid dispersion carrier, significantly increasing the dissolution rate and bioavailability of poorly soluble drugs.
2. Daily Chemical Industry: Used as a humectant in toothpaste (replacing or partially replacing glycerol) to prevent the paste from drying out; as a conditioning agent in shampoos and body washes to provide a smooth feel and reduce the irritation of surfactants; as a basic moisturizing factor in creams, lotions, and other skincare products, forming a hydrated film to increase skin moisture content.
3. Textile Industry: Serves as an efficient antistatic agent and lubricant, imparting smoothness and cohesion to synthetic fibers, reducing friction static, and improving fabric hand feel; also used as a penetrating and lubricating medium during the mercerization process of cotton yarn or fabric.
4. Rubber and Plastics Industry: Used as an efficient mold release agent to help products separate smoothly from molds during vulcanization or molding, ensuring a clean surface; also as a lubricating dispersant to improve compatibility between fillers and the base resin.
5. Papermaking Industry: Used in coating formulations for coated paper as a lubricant to improve coating fluidity and prevent roll sticking; simultaneously acts as a humectant plasticizer to control paper moisture content, preventing warping.
6. Metalworking: Used as a core additive in water-based quenchants to adjust the cooling rate, reducing quenching deformation and cracking; provides boundary lubrication in cutting fluids, with very low ash content particularly suitable for precision machining.
7. Pesticide Formulations: Serves as a dispersing and binding carrier for wettable powders and water-dispersible granules, quickly disintegrating and dispersing active ingredients upon contact with water, significantly improving pesticide suspension rates and efficacy.