Polyethylene glycol PEG-400 (CAS: 25322-68-3) is a colorless transparent viscous liquid at room temperature, easily soluble in water, ethanol, and acetone, with a freezing point of about 4–8°C. Therefore, before use in low-temperature winter environments, it may need to be appropriately preheated to above room temperature to ensure good fluidity and convenient feeding. This product is a non-ionic surfactant with an HLB value of about 20, possessing strong hydrophilicity and excellent compatibility, capable of stable compounding with anionic, cationic, and other non-ionic systems. In terms of addition sequence, it is generally recommended to add it first to the main formulation system and stir evenly.
In practical operation, the application method of PEG-400 highly depends on specific industry scenarios. In the pharmaceutical field, when used as an ointment base or suppository base, it usually needs to be heated to 50–60°C to fully melt and mix with the active drug and other excipients, then cooled to form; when used as a liquid solubilizer, the poorly soluble drug can be dissolved in PEG-400 first, then slowly added to the aqueous phase. In the daily chemical field, when added as a humectant, the typical addition amount is about 2%–8% of the total formulation, and it can be added to either the water phase or oil phase before emulsification. In the textile and metal processing fields, as a lubricating or antistatic component, it is usually added at 1%–10% of the total working fluid and diluted with deionized water before use.
Due to the hygroscopic nature of PEG-400, after opening the drum, it should be used as soon as possible and always stored sealed to avoid prolonged exposure to air, which could lead to moisture absorption and reduced effective content. The recommended storage temperature is between 5°C and 30°C. During use, wear nitrile or neoprene protective gloves and chemical safety goggles, and maintain good ventilation in the operating environment. If only partial removal is needed, be sure to use clean and dry sampling tools to prevent impurities from contaminating the entire drum product.
| Item | Specification |
|---|---|
| Appearance (25°C) | Colorless transparent viscous liquid |
| Effective content | ≥99.5% |
| Average molecular weight | 380~420 |
| Hydroxyl value (mg KOH/g) | 264~300 |
| pH value (1%~5% aqueous solution) | 4.5~7.5 |
| Kinematic viscosity (25°C) | 90~120 mm²/s |
| Density (25°C) | 1.11~1.13 g/cm³ |
| Moisture | ≤0.5% |
| Freezing point | About 4~8°C |
| Flash point (open cup) | ≥200°C |
| HLB value | About 20 |
| Cloud point (1% aqueous solution) | >100°C |
Pharmaceutical preparations: When used as an ointment/suppository base, it is recommended to heat to 50~60°C to melt, then mix well with the active ingredient and cool to form; when used as a liquid solubilizer, first dissolve the drug in PEG-400, then add dropwise to the aqueous phase, with the addition amount depending on the solubility of the drug, generally 5~20 times the amount of the active drug.
Daily chemical care products: As a humectant and lubricant, the recommended addition amount is 2%~8% of the total formulation, which can be added to the water phase and stirred well before emulsification, suitable for creams, lotions, shampoos, and toothpaste.
Textile processing: When used as an antistatic agent or softening finishing agent, it is recommended to prepare a 5%~15% stock solution, and further dilute to a working concentration of 0.5%~2% for padding or spraying treatment before use.
Metalworking fluids: As a lubricating component, the recommended addition amount is 5%~20% of the concentrate formulation, and after blending with other functional additives, dilute to a working concentration of 5%~10% before use.
Paints and inks: As a pigment dispersant or plasticizer, the recommended addition amount is 10%~50% of the pigment mass. First premix and grind with the pigment, then add to the base formulation.
Pesticide formulations: As an emulsifying wetting agent, the recommended addition amount is 5%~15% of the total formulation, and thoroughly mix with the pesticide active ingredient and solvent before adjusting to the final concentration.